There is no mention of any comment until Jesus comes to Peter. Either there was dead silence as Jesus washed the first few, or Peter may have been the first. At any rate, Peter does not hesitate to say something. “Peter, we may suppose, drew his feet up, as he spoke, in his impulsive humility” (Bernard). Peter’s question is the result of surprise, reverance, and misunderstanding.

“saw” the verb means to fix the eyes for a moment upon an object, or, more characteristically, a searching look placed upon an individual.  This doesn’t tell us much, however. I wonder what kind of look John fixed upon Jesus.  RWP states that the tense of the verb “vividly pictures the rapture of John in this vision of Jesus.”  I’ll bet that he was so struck with awe and worship that there were tears in his eyes. 

“Look, the Lamb of God” = Why did he say this to the 2 disciples standing with him?  His disciples knew why and they acted upon it as recorded in the next verse.

John’s mission was to point men to Jesus or, as the Geneva Bible points out, “John gathers disciples not to himself, but to Christ.” Morris comments upon John’s sending his disciples to follow Jesus in this way:

Let us not overlook the light all this sheds on John’s greatness.  It is not particularly easy to attach disciples firmly to oneself when one is calling for a strenuous following of the right.  But when this has been done, it is the mark of a truly great man that he can gently, but firmly, detach them, so that they may go after a greater. (p. 156)

This is at least the third time John has seen Jesus and, as far as we know, the last.