Parashas Bo · Shemos 12:18 · TT note 2
Torah Temimah on Shemos 12:18, note 2 (on בָּעֶרֶב תֹּאכְלוּ מַצּוֹת) points to Pesachim 120a.
Sefaria — Exodus 12:18
Sefaria — Torah Temimah on Exodus 12:18
Sefaria — Pesachim 120a
E-Daf — Pesachim 120a
English: I have only [the obligation] when the Temple stands; when the Temple does not stand — from where? Scripture says “in the evening you shall eat matzos” — the verse fixed it as an obligation.
Matzah of the Seder night is a Torah obligation even without the Temple.
Unlike the korban Pesach, eating matzah on the first night remains a chova in our time.