Two different Greek words for “gift” emphasize the perfection and inclusiveness of God’s graciousness. The first denotes the act of giving, and the second is the object given. Everything related to divine giving is adequate, complete, and beneficial.
“Father of lights” is an ancient Jewish expression for God as the Creator, with “lights” referring to the sun, moon, and stars.
No variation or shadow of turning. From man’s perspective, the celestial bodies have different phases of movement and rotation, change from day to night, and vary in intensity and shadow. But God does not follow that pattern-He is changeless.
Commentary from the MacArthur study Bible, notes for James 1:17.