וכי תזבחו זבח תודה לד' לרצונכם תזבחו
Rashi understands this pasuk as an enjoinment to one who offers a Korban Todah, Thanksgiving-offering, to maintain the proper kavanah, positive intention, that it all be eaten on that day. If one has intention to prolong the eating until the next day, he not only disqualifies the korban, but he also loses favor for himself in the eyes of Hashem. A korban achieves efficacy if the individual offering the sacrifice adheres to the prescribed Biblical rules concerning its offering. Otherwise, the korban is invalid. L’retzonchem is required in order for a korban to be effective. Horav Avraham Pam, zl (cited…