Commentaire sur Samuel 2 22:2

My Rock, my Fortress. They are words denoting strength. Rock is obvious in its connotation [of strengh]. Fortress is [a reference to] a fortress amongst the forests that is called flassant in O.F. It is [also] a reference to the miracle that occurred by the rock at the crossroads⁵Shmuel I, 23:28. and the fortresses of the forest.⁶Ibid, 23:19. Dovid’s location was betrayed to Shaul but eventually when Shaul reached the crossroads, he chose not to chase after Dovid.

My Rescuer. He saved me when I was with Yisroel's army at war and other times He saved me when I was alone⁷Rashi is explaining why Dovid in effect, says “me” twice. מְפַלְטי means “My Rescuer” and לי means “me”. for example [He saved me] from (the inhabitants of Nov)[“Yishbi-Benov”].