# removed him from the kingship

This expression means God caused Saul to stop being king. Alternate translation: "rejected Saul from being king"

# he raised up David to be their king

"God chose David to be their king"

# their king

"the king of Israel" or "the king over the Israelites"

# It was about David that God said

"God said this about David"

# I have found

"I have observed that"

# to be a man after my heart

This expression means he "is a man who wants what I want." (See: [[rc://en/ta/man/translate/figs-idiom]])