The difference between these ideas is hard to grasp. Perhaps by this distinction of expressions he indicates temporal and eternal goods, material and spiritual goods, earthly and higher goods, and the like.
In general, he signifies that God is the source of every kind and all kinds of good, and only of goods, not evils. He alone is the source of goods.
"From above" means from heaven; cf. Acts 14:17; Acts 26:13; Jn 6:32-33.
"From the Father of lights" means from the source of every light, both spiritual and sensible. Light is the symbol of good, as darkness is the symbol of evil.
The Father, the source of all lights, is therefore the source of every good. He Himself is Light and good, and in Him there is no darkness, no evil whatever; cf. Jn 1:4-5.
Consequently no darkness or evil can proceed from Him, such as temptation unto perdition.
"With whom there is no change," and so forth, strengthens and clarifies the name Father of lights. The light of the heavenly lights or luminaries, which serves as a symbol of divine spiritual light, is changeable and not constantly the same.
The Light of the Father of these lights never changes and is always the same. Expressed without imagery, God does not waver between good and evil.
In Him and from Him there is immutably and always only what is good, without the slightest shade of evil. Evil is incompatible with His very nature, as the holiest and purest Being.
Blessed Theophylact, understanding by the Father of lights God, understands by the lights either the angelic powers or people illumined by the Holy Spirit.
In any case, these are secondary lights, immeasurably below the one Father of lights. In Him, or with Him, "there is no change, for He Himself cries out through the prophet: 'I am, and I do not change'" (Mal 3:6).
The expression "shadow of turning" means that one cannot even think of any change in God (Theophylact).
If Scripture contains expressions that seem to indicate changeability in God, for example that He is angry, repents, and the like, these are only anthropomorphic expressions of God's relations to man.
Immutable in His inward being, He changes only His relations to man, according to human changeability.
As the greatest gift of God to men from among all His givings and gifts to them, the Apostle points to the gift of regeneration by the word of truth.
He does this to prove that only what is good, and in no way what is evil, can descend from God.