Mahapadanasutta 1.27.1

1.27.1

Dhammatā esā, bhikkhave, yadā bodhisatto mātukucchimhā nikkhamati, visadova nikkhamati amakkhito udena amakkhito semhena amakkhito ruhirena amakkhito kenaci asucinā suddho visado.

It’s normal that, when the being intent on awakening emerges from his mother’s womb, he emerges already clean, unsoiled by waters, mucus, blood, or any other kind of impurity, pure and clean.