(Exodus 23:18) "You shall not slaughter in the presence of chametz the blood of My sacrifice": You shall not slaughter the Pesach offering while chametz is still present. These are the words of R. Yishmael. R. Akiva says: This tells me only of slaughtering. Whence do I derive (the same for) sprinkling (of the blood)? From (Devarim 12:27) "the blood of your sacrifices," (which equates the sprinkling of the blood with the sacrificing.) R. Yehudah says ("My sacrifice") — the sacrifice which is all Mine (i.e., which is entirely consumed). Which is that? The (afternoon) tamid, (which may not be slaughtered on Pesach eve in the presence of chametz.)