Deuteronomy 8:1-2

All the commandment which I command thee this day shall ye observe to do, that ye may live, and multiply, and go in and possess the land which Jehovah sware unto your fathers. And thou shalt remember all the way which Jehovah thy God hath led thee these forty years in the wilderness, that he might humble thee, to prove thee, to know what was in thy heart, whether thou wouldest keep his commandments, or not.