Yosef Karo, Shulchan Aruch — Yoreh Deah 262
“ And even if we do a milah not at its time we don't do except for during the day. Ab) If he is over and circumcises at night he is required to redo it and do hatif dum brit (draw some blood) mishna there Circumcises before the eigth day and during the day is is ok the rosh, in perek Rabbi Eliezer de Milah, Rashba and not as we will learn in 264ב We don't circumcise a sick child until it is healthy. And we learn that we don't circumcise him until seven complete days after he is better. ”
