ישעיהו נ:ו פירוש: רש״י ואבן עזרא

I gave my back to smiters He said to me, Isaiah, My children are obstinate; My children are bothersome. [You may go] on the condition that you do not become angry with them. I said to Him, On that condition.

I gave my back, etc. I did not care that I had to expose my back to strokes for the sake of His name.