Albert Barnes on John 3:29

He that hath the bride, &c. This is an illustration drawn from marriage. The bride belongs to her husband. So the church, the bride of the Messiah, belongs to him. It is to be expected, therefore, and desired, that the people should flock to him.

But the friend of the bridegroom. He whose office it is to attend him on the marriage occasion. This was commonly the nearest friend, and was a high honour.

Rejoiceth greatly. Esteems himself highly honoured by the proof of friendship.

The bridegroom's voice. His commands, requests, or conversation.

This is my joy, &c. "I sustain to the Messiah the relation which a groomsman does to the groom. The chief honour and the chief joy is not mine, but his. It is to be expected, therefore, that the people will come to him, and that his success will be great." The relation of Christ to the church is often compared with the marriage relation, denoting the tenderness of the union, and his great love for his people. Comp. Isa 62:5, Rev 21:2,9, 22:17, Eph 5:26,27,32 2Cor 11:2.

(d) "bride" Song 4:8-12, Jer 2:2, Eze 16:8, Hoss 2:19,20, Mt 22:2 2Cor 11:2, Eph 5:25,27, Rev 21:9

(e) "friend of the bridegroom" Jn 6:33, 8:23, Eph 1:20,21