But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed.
Ask in faith - i:e., the persuasion that God can and will give James begins and ends with faith. In the middle of the letter he removes hindrances to faith, and shows its true character (Bengel).
Wavering, х diakrinomenos (G1252)] - between belief and unbelief. Compare the Israelites who seemed to believe in God's power, but leant to unbelief by 'limiting' it (Psalms 78:41). Contrast Acts 10:20; Romans 4:20 ("staggered not ... through unbelief;" literally, 'wavered not') (1 Timothy 2:8).
Like wave of the sea (Isaiah 57:20; Ephesians 4:14) [kludonizomenoi, like a wave] - 'tossed to and fro with every wind.'
Driven with the wind - from without.
Tossed - from within, by its own instability (Bengel). At one time cast on the shore of faith and hope, at another tolled Back into unbelief; at one time raised to the height of worldly pride, at another tossed in the sands of despair (Weisinger).