I have heard that on one occasion the Blessed One was staying near Savatthi, at Jeta's Grove, Anathapindika's monastery. Then Mahapajapati Gotami, together with about 500 other nuns, went to the Blessed One and, on arrival, having bowed down to him, stood to one side. As she was standing there she said to him, "Exhort the nuns, lord. Instruct the nuns, lord. Give the nuns a talk on Dhamma."
Now at that time the elder monks were taking turns in exhorting the nuns, but Ven. Nandaka didn't want to exhort the nuns when his turn came. So the Blessed One addressed Ven. Ananda: "Ananda, whose turn is it to exhort the nuns today?"
"Lord, everyone has taken his turn 1 in exhorting the nuns, except for Ven. Nandaka, here, who doesn't want to exhort the nuns when his turn comes."
Then the Blessed One addressed Ven. Nandaka: "Exhort the nuns, Nandaka. Instruct the nuns, Nandaka. Give the nuns a talk on Dhamma, brahman."
"As you say, lord," Ven. Nandaka replied. Then, early in the morning, having put on his robes and carrying his bowl & outer robe, he went into Rajagaha for alms. After his meal, on returning from his alms round, he went with a companion to Rajaka Park. The nuns saw him coming from afar and, on seeing him, arranged a seat and set out water for his feet. Ven. Nandaka sat down on the arranged seat and washed his feet. The nuns bowed down to him and sat to one side.
As they were sitting there, Ven. Nandaka said to them: "This will be a question-response talk, sisters. Where you understand, you should say, 'We understand.' Where you don't, you should say, 'We don't understand.' Where you are doubtful or perplexed, you should question me in response: 'How is this, venerable sir? What is the meaning of this?'"
"Venerable sir, we are gratified & delighted that you invite us in this way."
"So then, sisters, what do you think: Is the eye constant or inconstant?" "Inconstant, venerable sir." "And is that which is inconstant easeful or stressful?" "Stressful, venerable sir." "And is it fitting to regard what is inconstant, stressful, subject to change as: 'This is mine. This is my self. This is what I am'?"
"No, venerable sir."
"... Is the ear constant or inconstant?" "Inconstant, venerable sir." ...
"... Is the nose constant or inconstant?" "Inconstant, venerable sir." ...
"... Is the tongue constant or inconstant?" "Inconstant, venerable sir." ...
"... Is the body constant or inconstant?" "Inconstant, venerable sir." ...
"What do you think, sisters: Is the intellect constant or inconstant?" "Inconstant, venerable sir." "And is that which is inconstant easeful or stressful?" "Stressful, venerable sir." "And is it fitting to regard what is inconstant, stressful, subject to change as: 'This is mine. This is my self. This is what I am'?"
"No, venerable sir. Why is that? Because we have already seen it well as it actually is, with right discernment, that these six internal media are inconstant."
"Good, good, sisters. That's how it is for a disciple of the noble ones who has seen it as it actually is with right discernment.
"Now what do you think, sisters: Are forms constant or inconstant?" "Inconstant, venerable sir." "And is that which is inconstant easeful or stressful?" "Stressful, venerable sir." "And is it fitting to regard what is inconstant, stressful, subject to change as: 'This is mine. This is my self. This is what I am'?"
"No, venerable sir."
"... Are sounds constant or inconstant?" "Inconstant, venerable sir." ...
"... Are aromas constant or inconstant?" "Inconstant, venerable sir." ...
"... Are flavors constant or inconstant?" "Inconstant, venerable sir." ...
"... Are tactile sensations constant or inconstant?" "Inconstant, venerable sir." ...
"What do you think, sisters: Are ideas constant or inconstant?" "Inconstant, venerable sir." "And is that which is inconstant easeful or stressful?" "Stressful, venerable sir." "And is it fitting to regard what is inconstant, stressful, subject to change as: 'This is mine. This is my self. This is what I am'?"
"No, venerable sir. Why is that? Because we have already seen it well as it actually is, with right discernment, that these six external media are also inconstant."
"Good, good, sisters. That's how it is for a disciple of the noble ones who has seen it as it actually is with right discernment.
"Now what do you think, sisters: Is eye-consciousness constant or inconstant?" "Inconstant, venerable sir." "And is that which is inconstant easeful or stressful?" "Stressful, venerable sir." "And is it fitting to regard what is inconstant, stressful, subject to change as: 'This is mine. This is my self. This is what I am'?"
"No, venerable sir."
"... Is ear-consciousness constant or inconstant?" "Inconstant, venerable sir." ...
"... Is nose-consciousness constant or inconstant?" "Inconstant, venerable sir." ...
"... Is tongue-consciousness constant or inconstant?" "Inconstant, venerable sir." ...
"... Is body-consciousness constant or inconstant?" "Inconstant, venerable sir." ...
"What do you think, sisters: Is intellect-consciousness constant or inconstant?" "Inconstant, venerable sir." "And is that which is inconstant easeful or stressful?" "Stressful, venerable sir." "And is it fitting to regard what is inconstant, stressful, subject to change as: 'This is mine. This is my self. This is what I am'?"
"No, venerable sir. Why is that? Because we have already seen it well as it actually is, with right discernment, that these six consciousness-groups, too, are inconstant."
"Good, good, sisters. That's how it is for a disciple of the noble ones who has seen it as it actually is with right discernment.
"Just as when the oil in a burning oil lamp is inconstant & subject to change, its wick is inconstant & subject to change, its flame is inconstant & subject to change, its light is inconstant & subject to change. If someone were to say, 'The oil in that burning oil lamp is inconstant & subject to change, its wick is inconstant & subject to change, its flame is inconstant & subject to change, but as for its light, that is constant, everlasting, eternal, & not subject to change': would he be speaking rightly?"
"No, venerable sir. Why is that? Because the oil in that burning oil lamp is inconstant & subject to change, its wick is inconstant & subject to change, its flame is inconstant & subject to change, so how much more should its light be inconstant & subject to change."
"In the same way, sisters, if someone were to say, 'My six internal media are inconstant, but what I experience based on the six internal media — pleasure, pain, or neither pleasure nor pain — that is constant, everlasting, eternal, & not subject to change': would he be speaking rightly?"
"No, venerable sir. Why is that? Because each feeling arises dependent on its corresponding condition. With the cessation of its corresponding condition, it ceases."
"Good, good, sisters. That's how it is for a disciple of the noble ones who has seen it as it actually is with right discernment.
"Just as when the root of a great, standing tree — possessed of heartwood — is inconstant & subject to change, its trunk is inconstant & subject to change, its branches & foliage are inconstant & subject to change, its shadow is inconstant & subject to change. If someone were to say, 'The root of that great, standing tree — possessed of heartwood — is inconstant & subject to change, its trunk is inconstant & subject to change, its branches & foliage are inconstant & subject to change, but as for its shadow, that is constant, everlasting, eternal, & not subject to change': would he be speaking rightly?"
"No, venerable sir. Why is that? Because the root of that great, standing tree — possessed of heartwood — is inconstant & subject to change, its trunk is inconstant & subject to change, its branches & foliage are inconstant & subject to change, so how much more should its shadow be inconstant & subject to change."
"In the same way, sisters, if someone were to say, 'My six external media are inconstant, but what I experience based on the six internal media — pleasure, pain, or neither pleasure nor pain — that is constant, everlasting, eternal, & not subject to change': would he be speaking rightly?"
"No, venerable sir. Why is that? Because each feeling arises dependent on its corresponding condition. With the cessation of its corresponding condition, it ceases."
"Good, good, sisters. That's how it is for a disciple of the noble ones who has seen it as it actually is with right discernment.
"Just as if a skilled butcher or butcher's apprentice, having killed a cow, were to carve it up with a sharp carving knife so that — without damaging the substance of the inner flesh, without damaging the substance of the outer hide — he would cut, sever, & detach only the skin muscles, connective tissues, & attachments in between. Having cut, severed, & detached the outer skin, and then covering the cow again with that very skin, if he were to say that the cow was joined to the skin just as it had been: would he be speaking rightly?"
"No, venerable sir. Why is that? Because if the skilled butcher or butcher's apprentice, having killed a cow, were to ... cut, sever, & detach only the skin muscles, connective tissues, & attachments in between; and ... having covered the cow again with that very skin, then no matter how much he might say that the cow was joined to the skin just as it had been, the cow would still be disjoined from the skin."
"This simile, sisters, I have given to convey a message. The message is this: The substance of the inner flesh stands for the six internal media; the substance of the outer hide, for the six external media. The skin muscles, connective tissues, & attachments in between stand for passion & delight. And the sharp knife stands for noble discernment — the noble discernment that cuts, severs, & detaches the defilements, fetters, & bonds in between.
"Sisters, there are these seven factors for awakening 2 through whose development & pursuit a monk enters & remains in the fermentation-free awareness-release & discernment-release,3 having directly known & realized them for himself right in the here & now. Which seven? There is the case where a monk develops mindfulness as a factor for awakening dependent on seclusion, dependent on dispassion, dependent on cessation, resulting in relinquishment. He develops analysis of qualities as a factor for awakening ... persistence as a factor for awakening ... rapture as a factor for awakening ... serenity as a factor for awakening ... concentration as a factor for awakening ... equanimity as a factor for awakening dependent on seclusion, dependent on dispassion, dependent on cessation, resulting in relinquishment. These are the seven factors for awakening through whose development & pursuit a monk enters & remains in the fermentation-free awareness-release & discernment-release, having directly known & realized them for himself right in the here & now."
Then, having exhorted the nuns with this exhortation, Ven. Nandaka dismissed them, saying, "Go, sisters. The time has come." The nuns, delighting in and approving of Ven. Nandaka's exhortation, got up from their seats, bowed down to him, circumambulated him — keeping him to the right — and went to the Blessed One. On arrival, having bowed down to the Blessed One, they stood to one side. As they were standing there, the Blessed One said to them, "Go, nuns. The time has come." So the nuns, having bowed down to the Blessed One, circumambulated him — keeping him to the right — and departed.
Then not long after the nuns' departure the Blessed One addressed the monks: "Monks, just as on the uposatha day of the fourteenth, people at large are not doubtful or perplexed as to whether the moon is lacking or full, for it is clearly lacking; 4 in the same way, even though the nuns are gratified with Nandaka's Dhamma-teaching, their resolves have not yet been fulfilled." So he addressed Ven. Nandaka: "In that case, Nandaka, exhort the nuns again tomorrow with the exact same exhortation."
"As you say, lord," Ven. Nandaka replied. Then, after the night had passed, early in the morning, having put on his robes and carrying his bowl & outer robe, he went into Rajagaha for alms ... [as before, from "Then the Blessed One addressed Ven. Nandaka" up to:]
Then not long after the nuns' departure the Blessed One addressed the monks: "Monks, just as on the uposatha day of the fifteenth, people at large are not doubtful or perplexed as to whether the moon is lacking or full, for it is clearly full; in the same way, the nuns are gratified with Nandaka's Dhamma-teaching, and their resolves have been fulfilled. Of these 500 nuns, the most backward is a stream-winner, not destined for the planes of deprivation, headed to self-awakening for sure."
That is what the Blessed One said. Gratified, the monks delighted in the Blessed One's words.
Notes
1. This phrase is not in the PTS edition.
2. The commentary explains that Ven. Nandaka introduces the topic of the seven factors of awakening here to indicate where the nuns have more work to do in their practice. From the questions and answers, it is obvious that they have developed the second factor of awakening — analysis of qualities (or dhammas) — which is the factor associated with insight and discernment. However, for their resolves to be fulfilled, they need to focus on developing the factors associated with tranquillity and concentration.
3. On awareness-release and discernment-release, see AN 2.30 and AN 9.44. Discernment-release is always transcendent; awareness-release, only when fermentation-free.
4. Apparently, in the Buddha's time, the 29-day lunar month was divided so that the half ending in the new moon uposatha had fourteen days, and the half ending in the full moon uposatha, fifteen days. How they compensated for the fact that the lunar month is not exactly 29 days is not known.