SB 3.12.30
naitat purvaih krtam tvad ye
na karisyanti capare
yas tvam duhitaram gaccher
anigrhyangajam prabhuh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O father, this performance in which you are endeavoring to complicate yourself was never attempted by any other Brahma, nor by anyone else, nor by you in previous kalpas, nor will anyone dare to attempt it in the future. You are the supreme being in the universe, so how is it that you want to have sex with your daughter and cannot control your desire?
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The post of Brahma is the supermost post in the universe, and it appears that there are many Brahmas and many universes besides the one in which we are situated. One who fills this post must be ideal in behavior, for Brahma sets the example for all living entities. Brahma, the living entity who is the most pious and spiritually elevated, is entrusted with a post next to that of the Personality of Godhead.