Albert Barnes Commentary Psalms 103:13

"Like as a father pitieth his children, So Jehovah pitieth them that fear him." — Psalms 103:13 (ASV)

Like as a father pitieth his children—Hebrew: “Like the compassion of a father for his children.” See the notes at Matthew 7:7-11. God often compares Himself to a father, and it is by extending our ideas of what constitutes the parental character that we gain our best conceptions of God’s character. See the notes at Matthew 6:9.

What is referred to here is the natural affection of a parent for their child; the tender love a parent bears for their offspring; the disposition to care for its needs; the readiness to forgive when an offense has been committed. Compare Luke 15:22-24. Such, in an infinitely higher degree, is the compassion—the kindness—that God has for those who love Him.

So the LORD pitieth them that fear him—He has compassion on them; He shows a fatherly feeling toward them.