Planning is great. We should be thoughtful about much in this world. But sometimes our desire for certainty and control can lead us to focus so much on certainty, that we make choices apart from God, for our own peace of mind.
Contracts are agreements between two people or parties that are created to protect each signee. A covenant is an agreement between two people or parties that is meant to protect the other person. In Genesis 15 God formally makes his promise to Abram, and makes clear the terms of what it will take to uphold the covenant. God reminds Abram (and us) that much in this world is far more about God and less about us.
After some time Abram and his nephew find themselves in a place of conflict. So they are given a choice, options of how to move forward. The choice seems clear from a human perspective, but sometimes God’s wisdom is not the same as human wisdom, and His plans do not match ours.