William Burkitt on Matthew 18:19

Here we have a gracious promise made by Christ of his presence with all his members in general, and with is ministers in special; whenever they meet together in his name, that is by his authority, in obedience to his command, and with an eye to his glory. Whenever they celebrate any sacred institution of his, or execute any church-censures, he will be in the midst of them, to quicken their prayers, to guide their councils, to ratify their sentence, to accept their endeavours.

Learn, 1. That Christ will be graciously present with and amongst his people, whenever they assemble and meet together in his name, be it ever so small a number.

2. That Christ will, in a special manner, be present with the guides and officers of his church, to direct their censures, and to confirm the sentence passed in his name, and pronounced by his authority upon obstinate offenders.