Paul is personally strengthening the admonitions by which he is putting them right. The one from whom they have heard Christian teaching is coming to visit. If so, they will be all the more concerned not to be ashamed when he arrives.
5. "But I will come to you," says he, "when I shall have passed through Macedonia." This he had said also above; then however with anger: at least he added, [1 Corinthians 4:19] "And I will know not the speech of them that are puffed up, but the power:" but here, more mildly; that they might even long for his coming. Then, that they might not say, "Why is it that you honor the Macedonians above us?" he said not, "When I depart," but, "When I shall have passed through Macedonia; for I do pass through Macedonia."
[AD 384] Ambrosiaster on 1 Corinthians 16:5-6