Albert Barnes Commentary 2 Samuel 1:16

"And David said unto him, Thy blood be upon thy head; for thy mouth hath testified against thee, saying, I have slain Jehovah`s anointed." — 2 Samuel 1:16 (ASV)

David might well think his sentence was just, though severe, for he had more than once expressed the deliberate opinion that no one could lift up his hand against the Lord’s anointed and be guiltless (see 1 Samuel 24:6; 26:9, 11, 16).