Question: Can females ordain twice as Buddhist nuns?
Answer: No, according to the record of this event and rule by the Buddha in the Mūlasarvāstivāda Vinaya’s Section On Miscellaneous Matters’ 30th Scroll《根本说一切有部毘奈耶。杂事》卷三十, as translated by the Tripiṭaka Dharma Master Yijing (三藏法师义净) :
尔时室罗伐城有一长者。娶妻未久遂即有娠。月满生女生已父亡。母养既大其母 亦终。後时吐罗难陀尼因乞食入其舍。见女问曰。汝属於谁。答言。圣者我无依怙曾未属人。报言。若如是者何不出家。女曰。谁与我出家。尼曰。我能与汝可随我去。 彼即随行至尼住处。便与出家。後被烦恼之所牵缠遂便还俗。时吐罗难陀尼。因出乞食遇见其女。问言。少女如何得活。答言。圣者我无依怙辛苦存生。报言。若尔何故更不出家。答曰。我已还俗谁与出家。尼曰我能。即与出家遂行乞食。
As summarised… Once, at Śrāvastī, the bhikṣuṇī (Buddhist nun) Sthūlanandā encountered an orphaned girl on her alms round. Realising she was without any support, she encouraged and guided her to be a nun. Later, due to being enmeshed with afflictions, the girl returned to the lay life. Sthūlanandā again encountered her later, and asked how she was surviving. The girl replied that as she is without any support, she is living with much hardship. Sthūlanandā asked her to consider being a nun again, which she again did, through her.
When elder Brahmins saw this, they together ridiculed her, saying how the Buddha’s nuns might sometimes renounce to practise the pure practices, or sometimes return to the defiled lay life, if they feel like doing so. When all the nuns heard this, they told this to the monks, who told this to the Buddha.
The Buddha thus decided that as nuns who return to the lay life have such misgivings, from then onwards, all nuns who returned to the lay life are not able to again renounce to be nuns. This is to prevent others from sneering at, to damage the (reputation of) Buddha’s Dharma teachings. As such, once nuns give up their (monastic) Dharma robes, having already returned to the lay life, they should not again be enabled to renounce to be nuns. If with those who re-renounce, the teacher (or ordination master) attains transgression from breaching the Dharma (as he or she should now be aware of the above rule that disqualifies reordination of nuns and reordained nuns).
Question: Why did the Buddha forbid repeated ordination of women?
Answer: All precepts and rules were set by the Buddha for facilitating spiritual cultivation, to help all to avoid evil, do good and purify the mind. Precepts for monastics were created by the Buddha when specific incidents occurred, as recorded in the Vinaya, that exemplify why each precept or rule is needed. As expressed by the incident above, the Buddha knew that females are generally more easily emotionally attached to their afflictions and worldly life.
As such, other than to not let others ridicule the Triple Gem (of the Buddha, Dharma and Saṅgha) for repeated ordination of the same ones who returned to the lay life, he set the rule allowing only one-time ordination for females, to ensure that their determination to be fully committed to the monastic life is firm. This rule was made out of compassion, to uphold the respectable reputation of the Triple Gem stably to best benefit all, and to facilitate all females’ clear commitment.
Similar Vinaya quotes:
Letter By Great Master Yinguang:
Are All In ‘Monastic’ Robes Beyond Question?