John Wesley on Isaiah 58:5

Chosen - Approve of, accept, or delight in, by a metonymy, because we delight in what we freely chuse. For a day - This may be understood, either for a man to take a certain time to afflict his soul in, and that either from even to even, Lev 23:32, or from morning to evening, or for a little time. Wilt thou call - Canst thou suppose it to be so? A fast - It being such an one as has nothing in it, but the dumb signs of a fast, nothing of deep humiliation appearing in it, or, real reformation proceeding from it. Acceptable day - A day that God will approve of.