With Ambaṭṭha 2.12.5

2.12.5

Atha kho bhagavā tathārūpaṃ iddhābhisaṅkhāraṃ abhisaṅkhāsi. Yathā addasa ambaṭṭho māṇavo bhagavato kosohitaṃ vatthaguyhaṃ.

Then the Buddha used his psychic power to will that Ambaṭṭha would see his private parts sheathed in a foreskin.