English: “On the tenth of this month” — “this” is a limitation, to teach that the Pesach of Egypt was taken on the tenth, but the Pesach of the generations is not [required to be] taken on the tenth.
On the daf / in context: See the cited source for the full section.
Type of Learning
Derash on the verse (Pesachim 96a) — not a formal named middah of the 13.
What Is Learned
Taking the lamb on the tenth was required for the Egyptian Pesach, not as an absolute rule for all generations.