God is my salvation (comp. Psalms 27:1; Psalms 38:22, etc.). The employment of the abstract "salvation" for the concrete "Savior" is extremely common. The Lord Jehovah; literally, Jah Jehovah—a combination which occurs only here and in Isaiah 26:4, where it is again used as an encouragement to perfect confidence and trust.
Is my strength … salvation. This is quoted from the song of Moses (Exodus 15:2), which the prophet has throughout in his thoughts.