It was just a stone like any other stone.
There were other thousands of stones in the valley, and Prophet Ibrahim alihissalam could have stepped on many of them. But none of them have preserved the imprinted marks of the foots of prophet Ibrahim alaihissalam on them, except this one. The only reason that can explain this strange phenomena is that; Sayyiduna Ibrahim Alaihissalam supplicated standing on it and requested the Almighty to grant his Beloved in his Descendants. or to make him(Sayyiduna Ibrahim) the Grandfather of Muhammad (Sallellahu Alaihi Wa sallim). And the stone preserved that great moment in this way, which is till date witnessed by everyone.
Shaykh-ul-Islam Dr Muhammad Tahir-ul-Qadri