English: “You shall not spare and you shall not conceal him” — Rabbah bar Rav Huna said: In all cases a son may not be appointed an agent to strike or curse his father, except for a mesis.
On the daf / in context: Even the ordinary filial protections are suspended when the father is a mesis; a son may participate in the required severity.
Type of Learning
Derash on the verse (Sanhedrin) — a son may act against a mesis father.
What Is Learned
A son may serve as an agent to strike or curse his father only when that father is a mesis.