Reassurance for Abram
It is of interest that God did not speak to Abram (so far as Scripture informs us, at least) until after he had made his decision to separate. This fact is not incidental, but fundamental, for we read, “And the Lord said to Abram, after Lot had separated from him, … ” (Genesis 13:14).
God’s call of Abram (12:1-3), so far as we can discern, was to Abram alone. So also was the confirmation in chapter 13. God had commanded Abram to leave his relatives (12:1). Blessing could not come apart from obedience to God’s revealed will, and neither would reassurance. Humanly speaking, the only thing which stood in the way of divine blessing was human disobedience. God removed that barrier by providentially separating Lot, and now the promise of God is restated.
That can happen for us today. If we "miss it," just repent and then go back and DO what the last thing the Lord said for you to do!