2:1-4 The apostle desired to have a cheerful meeting with them; and he had written in confidence of their doing what was to their benefit and his comfort; and that therefore they would be glad to remove every cause of disquiet from him. We should always give pain unwillingly, even when duty requires that it must be given.

3. I wrote this same unto you—namely, that I would not come to you then (2Co 2:1), as, if I were to come then, it would have to be "in heaviness" (causing sorrow both to him and them, owing to their impenitent state). He refers to the first Epistle (compare 1Co 16:7; compare 1Co 4:19, 21; 5:2-7, 13).

sorrow from them of whom I ought to rejoice—that is, sorrow from their impenitence, when he ought, on the contrary, to have joy from their penitent obedience. The latter happy effect was produced by his first Epistle, whereas the former would have been the result, had he then visited them as he had originally proposed.

having confidence … that my joy is the joy of you all—trusting that you, too, would feel that there was sufficient reason for the postponement, if it interfered with our mutual joy [Alford]. The communion of saints, he feels confident in them "ALL" (his charity overlooking, for the moment the small section of his detractors at Corinth, 1Co 13:7), will make his joy (2Co 2:2) their joy.