Albert Barnes Commentary Psalms 144:1

"Blessed be Jehovah my rock, Who teacheth my hands to war, [And] my fingers to fight:" — Psalms 144:1 (ASV)

Blessed be the Lord my strength — Margin, as in Hebrew, “my rock.” See the notes at (Psalms 18:46), where the same expression occurs in the Hebrew.

Which teaches my hands to war — Hebrew, “To the war.” See the notes at (Psalms 18:34). The Hebrew is not precisely alike, but the sense is the same.

And my fingers to fight — Hebrew, my fingers to the fight. That is, He teaches my fingers so that I can skillfully use them in battle. Probably the immediate reference here is to the use of the bow — placing the arrow, and drawing the string.