Parashas Bo · Shemos 12:9 · TT note 1
Torah Temimah on Shemos 12:9, note 1 (on אַל תֹּאכְלוּ מִמֶּנּוּ) derives that an onen is forbidden the Pesach via gezeirah shavah with maaser.
Sefaria — Exodus 12:9
Sefaria — Torah Temimah on Exodus 12:9
English: The Pesach is forbidden to an onen. Why? It says “from it” regarding maaser — “I have not eaten of it in my mourning” — and it says “from it” regarding the Pesach; just as an onen is forbidden maaser, so an onen is forbidden the Pesach.
Gezeirah shavah (מִמֶּנּוּ–מִמֶּנּוּ) — middah of R’ Yishmael’s 13.
An onen may not eat of the Pesach, by comparison with maaser.