The word "Oh" here introduces an exclamation that expresses a hope or prayer. AT: "I hope that the salvation of Israel will come" or "I pray that the salvation of will come" (See: [[rc://en/ta/man/translate/figs-exclamations]])
# the salvation of Israel would come from Zion
The salvation represents God, the savior, whose temple is in Zion. AT: "the savior of Israel would come from Zion" or "God would come from Zion and save Israel" (See: [[rc://en/ta/man/translate/figs-metonymy]])
# When God brings back his people from the captivity