John Gill Commentary Psalms 18:37

"I will pursue mine enemies, and overtake them; Neither will I turn again till they are consumed." — Psalms 18:37 (ASV)

I have pursued my enemies, and overtaken them
Which may refer to David's pursuing the Amalekites, who overtook them and recovered all they had carried away, (1 Samuel 30:8 1 Samuel 30:10 1 Samuel 30:18 1 Samuel 30:19) ; so Kimchi explains it;

neither did I turn again till they were consumed ;
for not a man escaped, save four hundred young men that rode on camels and fled, (Psalms 18:17) .