Marc 14:19
And they began to be sorrowful, and to say unto him one by one, Is it I? and another said, Is it I?
Marc 14:20
And he answered and said unto them, It is one of the twelve, that dippeth with me in the dish.
Luc 22:23
And they began to enquire among themselves, which of them it was that should do this thing.
Jean 13:22-25
22
Then the disciples looked one on another, doubting of whom he spake.
23
Now there was leaning on Jesus' bosom one of his disciples, whom Jesus loved.
24
Simon Peter therefore beckoned to him, that he should ask who it should be of whom he spake.
25
He then lying on Jesus' breast saith unto him, Lord, who is it?
Jean 21:17
He saith unto him the third time, Simon, son of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep.