Mahāpadānasutta

Suttapiṭaka · Dīghanikāya · Mahāvagga · Vol. 10 · Section 16

[16] Bhikkhus, this is the natural law (dhammatā): when the Bodhisatta has descended into his mother's womb, no thought connected with the strands of sensual pleasure (kāmaguṇa) arises in the Bodhisatta's mother with regard to men; and the Bodhisatta's mother cannot be transgressed against by any man with a mind of lust. This is the natural law in this case.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.