Whether rightly or wrongly, whether as a gift of grace or as a taskmaster, second-temple Jews and their theologies form a part of the collective known as ISRAEL, which sought after a law of its own righteousness and used the commandments of God as a means for boasting (Rom. 9:32).
Actually, what matters is not how historic Jews viewed the law in relation to salvation but how GOD viewed the law in relation to salvation. And here is how God in the flesh, also a historical jew, viewed it:
ει δε θέλεις εις την ζωην εισελθειν, τήρησον τας εντολάς· (Mt. 19:17)
If you desire to enter into life, keep the commandments.
There is Jesus' soteriology of law. You are not first graciously given life by god in order that you might keep the commandments as a sort of grateful response. The commandments appear first to someone without life (ie. life eternal, so 19:16), and he then must keep them in order to enter it.