All the way, i.e. all the events which befell thee in the way, the miraculous protections, deliverances, provisions, instructions which God gave thee; and withal the frequent and severe punishments of thy disobedience. To know what was in thine heart, i.e. that thou mightest discover to thyself and others that infidelity, inconstancy, hypocrisy, apostacy, rebellion, and perverseness, which lay hid in thy heart; the discovery whereof was of singular use, both to them and to the church of God, in all succeeding ages.
Related Commentaries of Deuteronomy 8:2
Deuteronomy 8:2
2 And thou shalt remember all the way which the LORD thy God led thee these forty years in the wilderness, to humble thee, and to prove thee, to know what was in thine heart, whether thou wouldest keep his commandments, or no.