It was as a result of their unbelief and rebellion. In Your Astrology Language Review fact, a major factor that delayed them was that God wanted (as He promised them) all the generation that rebelled against Him to die in the wilderness. Remember how they refused to believe the report of Caleb and Joshua, instead they chose to believe the 'Negative Ten" against the word and promises of God. This made God to send them back into the wilderness. In fact, Israel stayed about 40 years in the wilderness. A whole generation!
But our interest here is that God would always come back to move them forward. Whether they got stock by their own deeds, pleasure, enemy attacks or whatever, God's ultimate interest was to take them to the Promised Land. From our main texts, God acknowledged that the Israelites had stayed longer than necessary at those various points, and that it was time to depart, break camp and move to the next level. They had wandered around these mountains and wildernesses enough; they must arise and move into the land He had promised them by oaths and covenants.
I like the 'God said' dimension that Moses brought into these declarations. To move out from where you are to where you are supposed to be, you must of necessity know what God is saying to you. You must know the promises of God concerning your situation. You must fully appreciate and appropriate the word of God concerning you life.