John 1:29

We have in these verses an account of John's testimony concerning Jesus Christ, which he witnessed to his own disciples that followed him. As soon as ever Christ was baptized he was immediately hurried into the wilderness, to be tempted; and there he was forty days. During his absence John had continued to bear testimony to him, and to tell the people of him; but now at last he sees Jesus coming to him, returning from the wilderness of temptation. As soon as that conflict was over Christ immediately returned to John, who was preaching and baptizing. Now Christ was tempted for example and encouragement to us; and this teaches us, 1. That the hardships of a tempted state should engage us to keep close to ordinances; to go into the sanctuary of God, Psa 73:17. Our combats with Satan should oblige us to keep close to the communion of saints: two are better than one. 2. That the honours of a victorious state must not set us above ordinances. Christ had triumphed over Satan, and been attended by angels, and yet, after all, he returns to the place where John was preaching and baptizing. As long as we are on this side heaven, whatever extraordinary visits of divine grace we may have here at any time, we must still keep close to the ordinary means of grace and comfort, and walk with God in them.

— Matthew Henry's Concise Commentary (public domain)

seeth Jesus--fresh, probably, from the scene of the temptation. coming unto him--as to congenial company (Act 4:23), and to receive from him His first greeting. and saith--catching a sublime inspiration at the sight of Him approaching. the Lamb of God--the one God-ordained, God-gifted sacrificial offering. that taketh away--taketh up and taketh away. The word signifies both, as does the corresponding Hebrew word. Applied to sin, it means to be chargeable with the guilt of it (Exo 28:38; Lev 5:1; Eze 18:20), and to bear it away (as often). In the Levitical victims both ideas met, as they do in Christ, the people's guilt being viewed as transferred to them, avenged in their death, and so borne away by them (Lev 4:15; Lev 16:15, Lev 16:21-22; and compare Isa 53:6-12; Co2 5:21). the sin--The singular number being used to mark the collective burden and all-embracing efficacy. of the world--not of Israel only, for whom the typical victims were exclusively offered. Wherever there shall live a sinner throughout the wide world, sinking under that burden too heavy for him to bear, he shall find in this "Lamb of God," a shoulder equal to the weight. The right note was struck at the first--balm, doubtless, to Christ's own spirit; nor was ever after, or ever will be, a more glorious utterance.

— Jamieson-Fausset-Brown Commentary (public domain)