Psalms 18:50

“Great deliverance giveth he to his king - To David, as king. The word in the original, which is rendered “deliverance,” means properly salvations, and is here in the plural number. It refers not to one act of divine interposition, but to the many acts (referred to in the psalm) in which God had interposed to save him from danger and from death. The phrase “to his king” refers to the fact that God had appointed him to reign, and to administer the government for him. He did not reign on his own account, but he reigned for God, and with a view to do his will. And showeth mercy to his anointed - To him who had been set apart to the kingly office by a solemn act of anointing. Compare 1 Samuel…”

“His king - To the king whom God himself chose and anointed, and to all his posterity; and especially to the Messiah, who is called David's seed, Act 13:23; Rom 1:3. Next: Psalms Chapter 19”

“18:50 God appointed David, his anointed ruler, to bring order into God’s world (see Ps 2). Both David and his descendants received this responsibility.”

“Great: Psa 2:6, Psa 78:71, Psa 78:72, Psa 89:3, Psa 89:4, Psa 144:10; Sa1 2:10, Sa1 16:1; Act 2:34-36; Phi 2:9-11 to his: Psa. 89:20-38, Psa 132:10; Sa2 7:13; Ch1 17:11-14, Ch1 17:27; Isa 9:6, Isa 9:7; Luk 1:31-33, Luk 1:69; Rom 1:3, Rom 11:29; Gal 3:16 Next: Psalms Chapter 19”