Albert Barnes Commentary John 12:30

"Jesus answered and said, This voice hath not come for my sake, but for your sakes." — John 12:30 (ASV)

Came not because of me. Not to strengthen or confirm me; not that I had any doubts about my course, or any apprehension that God would not approve me and glorify his name.

For your sakes. To give you a striking and indubitable proof that I am the Messiah; that you may remember it when I am departed, and be yourselves comforted, supported, and saved.