One who had two infants, one to circumcise after the Sabbath and one to circumcise on the Sabbath, and he forgot and circumcised the one who was [to be circumcised] after the Sabbath on the Sabbath, he is liable; [if he had] one to circumcise before the Sabbath and one to circumcise on the Sabbath, and he forgot and circumcised the one who was [to be circumcised] before the Sabbath on the Sabbath, R’ Eliezer declares [him] liable for a sin offering. But R’ Yehoshua exempts [him].