Midrash su Levitico 22:29

1) (Vayikra 22:29) ("And when you sacrifice a sacrifice of thanksgiving to the L–rd, with your acceptance shall you sacrifice it. (Vayikra 22:30) On that day it shall be eaten.") Let this ("On that day, etc.") not be stated (i.e., it is already written in 7:15). If it is not to be understood as referring to eating per se, understand it as referring to slaughtering, i.e., the very beginning of the slaughtering should be with the intention of eating it on the day.

2) This tells me only of a thanksgiving offering. Whence do I derive the same for all offerings? From "And when you sacrifice a sacrifice," to include (all) sacrifices that are to be eaten in one day.

3) From (Vayikra 22:29): "And when you slaughter a sacrifice of thanksgiving to the L–rd, that it be acceptable for you shall you slaughter it. (Vayikra 22:30) On that day shall it be eaten." This need not be stated, (for we know it already). If it is not needed for (the halachah of) eating, learn it as applying to sacrifice, that its sacrifice at the outset must be with the thought of eating it for one day.