Reply To: Chidushim on Daf Yomi

ברכות יט,ב

The Rambam holds in Sefer Hamitzvos Root 1, that a rabbinical gezera or enactment is authorized by the Torah, under לא תסור, do not sway from the words they tell you right or left. He also holds that a biblical safek is according to the Torah be ruled leniently. The chazal say that their safek is ruled leniently whereas biblical safek is ruled stringently. So question is why, what is the difference when they are both biblical? They answer
הם אמרו והם אמרו, as the whole rule is instituted by chazal, they can decide how to deal with it.
The Rambam Hilchas Kilaim (10,29) explains that for wearing rabbinical kilaim (shatnez), the respect for the individual supersedes the issur, so we don’t tear it off him whereas for biblical kilaim, the issur supersedes the respect.