I am in a daf yomi shiur and before we started Pesachim I read the introduction in the Koren Steinzaltz Talmud where it is written that all grain offerings brought to the temple were unleavened and that no chametz was ever brought. This being so, why is the mizmor letodah prayer not recited chol hamoed Pesach? I had previously assumed it was because the thanksgiving offering was grain and therefore Chametz.

The prohibition of chametz (Vayikra 22, 11) is only against using it as part of the sacrifice on the alter (mizbe’ach), but the accompanying loaves which are sometimes eaten with the sacrifice, can be chametz, as by the korban Todah (thanksgiving offering). Accordingly, it was not brought during Pesach. With Love of Israel, Rav Ari Shvat