[587] Then this thought occurred to the Blessed One: "This young brahmin Uttara sees the thirty-two marks of a great man (mahāpurisalakkhaṇa) on me for the most part, except for two. Concerning two marks of a great man he is doubtful, uncertain, undecided, and unconvinced: whether the male organ is enclosed in a sheath, and the largeness of the tongue." Then the Blessed One performed such a feat of psychic power (iddhābhisaṅkhāra) that the young brahmin Uttara saw the Blessed One's male organ enclosed in a sheath. Then the Blessed One, extending his tongue, stroked back and forth over both ear openings; he stroked back and forth over both nostril openings; and he covered the entire circle of his forehead with his tongue.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.