I've always found that in the Old Testament, 'salvation' refers more or less exclusively to temporal salvation, and not necessarily justification, whereas of course in the New Testament, it more often than not (if not exclusively) refers to justification and the translation from the state of being damned to being a child of God.
A pertinent, relevant example is when non-Catholics quote Mary's Magnificat as proof that she thought herself to be in need of forgiveness (i.e. in reaction to the Catholic doctrine of the immaculate conception and sinlessness of Mary), because—the argument goes—salvation pertains to salvation from sin:
Luke 1:46-55 (DRB) And Mary said:
My soul doth magnify the Lord. 47 And my spirit hath rejoiced in God my Saviour. 48 Because he hath regarded the humility of his handmaid; for behold from henceforth all generations shall call me blessed. 49 Because he that is mighty, hath done great things to me; and holy is his name. 50 And his mercy is from generation unto generations, to them that fear him. 51 He hath shewed might in his arm: he hath scattered the proud in the conceit of their heart. 52 He hath put down the mighty from their seat, and hath exalted the humble. 53 He hath filled the hungry with good things; and the rich he hath sent empty away. 54 He hath received Israel his servant, being mindful of his mercy: 55 As he spoke to our fathers, to Abraham and to his seed for ever.
The above of course seems to be an allusion to Psalm 40:16 (DRB):
Let all that seek thee rejoice and be glad in thee : and let such as love thy salvation say always : The Lord be magnified.
I see nothing about sins, but I hear a lot of echoing of the temporal salvation language found in the Old Testament—Mary, and this Song, was still in the Old Testament period, technically speaking.
Cf. Psalm 62.
Does the Old Testament (always? ever?) use the word "salvation" in the New Testament sense of the word (salvation from sins and/or eternal damnation), such that the words of Mary (who lives on the cusp of the New Testament era) in Luke 1:46-47 necessitate she is speaking about salvation from sin necessarily, and not from something temporal?