Every instrument or machine created has to have some maintenance or recalibration from time to time. Everyone encounters a pothole or hits a curb that knocks a wheel out of alignment. Sometimes we need a spiritual recalibration, and we find that at an altar. That altar is a place of reference where we can return to remember the goodness of God and how He provides.
In our text, God was about to bring a group of people who had been in bondage for many years. As He was about to begin, God tells them to make a reference point so that they would remember where they had come from once they had received what God had in store for them. God changed the calendar to establish this new starting point. We all have that same opportunity, and God continually provides a new beginning at an altar. When we recognize that God wants to do something remarkable in our life, we can set out from a new beginning.