if you obey the LORD your God by keeping His commandments and statutes that are written in this Book of the Law, and if you turn to Him with all your heart and with all your soul.
These verses may be considered either as a conditional promise or as an absolute prediction. I. They are chiefly to be considered as a conditional promise, and so they belong to all persons and all people, and not to Israel only; and the design of them is to assure us that the greatest sinners, if they repent and be converted, shall have their sins pardoned...
Commenting on Deuteronomy 30:1-10
If thou shalt hearken unto the voice of the Lord thy God,.... Or rather, "for thou shalt hearken" (p); seeing it is before promised that the Lord would circumcise their hearts to love him, and they should obey his voice, Deu 30:6.
Deu 30:10 A renewed enforcement of the indispensable condition of salvation.