"At that time Śāriputra spoke to the daughter of the nāga king, saying: “You say that you will soon attain the highest path. This is difficult to believe. Why is this? The female body is polluted; it is not a fit vessel for the Dharma. How can you attain highest enlightenment?
“The buddha path is long. One can only attain it after diligently carrying out severe practices, and completely practicing the perfections over immeasurable kalpas. Moreover, the female body has five obstructions. The first is the inability to become a great Brahma. The second is the inability to become Śakra. The third is the inability to become Māra, and the fourth is the inability to become a universal monarch (cakravartin). The fifth is the inability to become a buddha. How can you with your female body quickly become a buddha? ...
The daughter said: “Through your transcendent powers watch me become a buddha even more quickly than that!”
Then the assembly there all saw the daughter of the nāga king instantly transform into a man."