Sayyiduna Abdullah bin Amr (may Allah be pleased with him) says: "Perform tawaf of this House and touch this Black Stone, for these were two stones that were sent down from Paradise. One of them has been taken up, and soon the other will also be taken up. If it does not happen as I have said, then whoever passes by my grave should say: 'This is the grave of Abdullah bin Amr (may Allah be pleased with him), the liar.'"
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الحج / 5484