Behold the Lamb of God! Hence appears more clearly what I have already stated, that when John perceived that he was approaching the end of his course, he labored incessantly to resign his office to Christ. His firmness too gives greater credit to his testimony. But by insisting so earnestly, during many successive days, in repeating the commendation of Christ, he shows that his own course was nearly finished. Here we see also how small and low the beginning of the Church was. John, indeed, prepared disciples for Christ, but it is only now that Christ begins to collect a Church. He has no more than two men who are mean and unknown, but this even contributes to illustrate his glory, that within a short period, without human aid, and without a strong hand, he spreads his kingdom in a wonderful and incredible manner. We ought also to observe what is the chief object to which John directs the attention of men; it is, to find in Christ the forgiveness of sins. And as Christ had presented himself to the disciples for the express purpose that they might come to him, so now when they come, he gently encourages and exhorts them; for he does not wait until they first address him, but asks, What do you seek? This kind and gracious invitation, which was once made to two persons, now belongs to all. We ought not therefore to fear that Christ will withdraw from us or refuse to us easy access, provided that he sees us desirous to come to him; but, on the contrary, he will stretch out his hand to assist our endeavors. And how will not he meet those who come to him, who seeks at a distance those who are wandering and astray, that he may bring them back to the right road?

Looking upon Jesus - Fixing his eyes intently upon him. Singling him out and regarding him with special attention. Contemplating him as the long-expected Messiah and Deliverer of the world. In this way all ministers should fix the eye upon the Son of God, and direct all others to him.
As he walked - While Jesus was walking.

And looking upon Jesus - Attentively beholding, εμβλεψας, from εν, into, and βλεπω, to look - to view with steadfastness and attention. He who desires to discover the glories and excellencies of this Lamb of God, must thus look on him. At first sight, he appears only as a man among men, and as dying in testimony to the truth, as many others have died. But, on a more attentive consideration, he appears to be no less than God manifest in the flesh, and, by his death, making an atonement for the sin of the world.
Behold the Lamb of God! - By this the Baptist designed to direct the attention of his own disciples to Jesus, not only as the great sacrifice for the sin of the world, but also as the complete teacher of heavenly truth.

(16) And looking upon Jesus as he walked, he saith, Behold the Lamb of God!
(16) Christ is set before us to follow, not as a vain shadow, but as our Mediator.

And looking upon Jesus as he walked,.... Either by them; or as he was going from them to his lodgings; it being toward the close of the day, when John had finished his work for that day, and the people were departing home: John fixed his eyes intently on Christ, with great pleasure and delight, and pointing at him,
he saith, behold the Lamb of God; as in John 1:29, where it is added, "which taketh away the sin of the world"; and which the Ethiopic version subjoins here.

looking--having fixed his eyes, with significant gaze, on Jesus.
as he walked--but not now to him. To have done this once (see on John 1:29) was humility enough [BENGEL].
Behold, &c.--The repetition of that wonderful proclamation, in identical terms and without another word, could only have been meant as a gentle hint to go after Him--as they did.

Behold the Lamb of God! On the preceding day John had recognized Jesus in a public discourse as "the Lamb of God that taketh away the sin of the world." Now he personally points the disciples to him.