I have heard the following story from an Islamic Scholar. Hopefully, it will be beneficial for all of us.
When a child is born, he or she usually gets some characteristics and features from his or her parents or from other family members from the past. For example, our eyes, ears, nose or some other organs of the body may resemble that of our parents or forefathers. There was a group of people in Arabia who had the knowledge of this particular science, that is they could tell who the baby resembles. When Prophet Muhammad (peace and blessing be upon him) was still a baby, his grandfather, Abdul Muttalib, took him to his lap and was greeting those who came for Pilgrimage (Hajj). That specific group of people was also present and while going around the Kabah they would stare at the feet of young Prophet Muhammad (SAW). After going around few times, they came to Abdul Muttalib and said that they have never seen any other baby whose feet resemble the feet of Prophet Ibrahim (AS). Only the feet of young Prophet Muhammad (SAW) resemble them. The footprint of Prophet Ibrahim (AS) is preserved and placed beside Kabah.