English: “They shall take for themselves, each man” — Rabbi Yitzchak said: An adult can acquire [on behalf of the household], but a minor cannot acquire.
On the daf / in context: See the cited source for the full section.
Type of Learning
Derash on the verse (Bavli) — not a formal named middah of the 13.
What Is Learned
A minor cannot take and acquire the Pesach lamb on behalf of others.