From sutta SA 2.218:
The renunciant Gotama is staying at Sāvatthī at the Jeta Grove in the Anāthapiṇḍika Park. And there is the nun Selā who took her robes and her begging bowl and entered Sāvatthī to beg for food. Having finished her meal, she cleaned her bowl, gathered her seat and has gone to the Andhavana forest. I shall disturb her!” Having thought this he changed into a young man, approached her and spoke a verse:
“Who is it that created beings, by whom were they made? Why are they called beings, from where do they arise?”
That time the nun Selā, having heard the verse thought: “Who is this? What a cheat! Is he a human or a non-human being?” She entered concentration and recognized he was King Māra. She answered with a verse:
“Māra, you have a wrong view of ‘beings’, saying and believing they actually exist as substantial entities. Conventional, empty they are but compounded entities there are in fact no ‘beings.’ Like when causes and various conditions converge and yield the use of a ‘chariot’.
From sutta SN 5.10:
Then Māra the Wicked, wanting to make the nun Vajirā feel fear, terror, and goosebumps, wanting to make her fall away from immersion, went up to her and addressed her in verse:
“Who created this sentient being? Where is its maker? Where has the being arisen? And where does it cease?”
Then the nun Vajirā thought, “Who’s speaking this verse, a human or a non-human?”
Then she thought, “This is Māra the Wicked, wanting to make me feel fear, terror, and goosebumps, wanting to make me fall away from immersion!”
Then Vajirā, knowing that this was Māra the Wicked, replied to him in verse:
“Why do you believe there’s such a thing as a ‘sentient being’? Māra, is this your theory? This is just a pile of conditions, you won’t find a sentient being here. When the parts are assembled we use the word ‘chariot’. So too, when the aggregates are present ‘sentient being’ is the convention we use.
And from Mil 3.1.1:
Very good! Your Majesty has rightly grasped the meaning of “chariot.” And just even so it is on account of all those things you questioned me about— The thirty-two kinds of organic matter in a human body, and the five constituent elements of being—that I come under the generally understood term, the designation in common use, of “Nāgasena.” For it was said, Sire, by our Sister Vajirā in the presence of the Blessed One:
“Just as it is by the condition precedent Of the co-existence of its various parts That the word ‘chariot’ is used, Just so is it that when the Skandhas Are there we talk of a ‘being.’”
Most wonderful, Nāgasena, and most strange. Well has the puzzle put to you, most difficult though it was, been solved. Were the Buddha himself here he would approve your answer. Well done, well done, Nāgasena!
Are these verses about the same nun? Is there anything more known about her?