Parashas Bo · Shemos 12:14 · TT note 3
Torah Temimah on Shemos 12:14, note 3 (on חֻקַּת עוֹלָם) points to Mechilta.
Sefaria — Exodus 12:14
Sefaria — Torah Temimah on Exodus 12:14
Sefaria — Mechilta
English: “An everlasting statute” — why is it said? Because it says “throughout your generations,” one might think a minimal two generations; therefore Scripture says “you shall celebrate it as an everlasting statute.”
Expansion of “generations” to all time via “everlasting statute.”
The festival is not limited to a few generations; it is an everlasting statute for all time.