James 4:15 - Ellicott's Commentary On The Whole Bible

For that ye ought to say.... — Referring to James 4:13, in some such a continuation of reproof as this: Woe unto you that say,.... instead of saying, “If the Lord will”.... In fact, it is a thing of the past, not of time, but completed action on the part of God — “If the Lord have willed it, we shall both live and do this or that.” Such is far, be it noted, from Fatalism, in even its best form, as under the teaching of Islam. The sovereignty of God is acknowledged, but with it is plainly recognised the existence of man’s free will, dependent, however, on the permission of the Most High for its fleeting duration and power. St. Paul speaks in similar tone of coming to Corinth, “if the Lord will” (1 Corinthians 4:19); and “God willing” (D.V.), “the reference of all the contingencies of the future to One supremely wise and loving Will, has been in all ages of Christendom the stay and strength of devout souls.”