The abstract noun "salvation" can be expressed with the verbs "save" or "rescue." Alternate translation: "from long ago). He will save us from our enemies" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
These two phrases mean basically the same thing and are repeated to emphasize how strongly their enemies are against them. (See: [[rc://en/ta/man/translate/figs-parallelism]])
The hand is a metonym for the power that the person uses the hand to exercise. Alternate translation: "power" or "control" (See: [[rc://en/ta/man/translate/figs-metonymy]])