It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The Black Stone will come on the Day of Resurrection bigger than Mount Abu Qubays. It will have a tongue and two lips, and they will testify in favour of the one who touched it (istilam) rightfully. And it is (as though) the right hand of Allah, the Mighty and Majestic, with which He shakes hands with His creation."
From Ata (may Allah have mercy on him), from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both), no one narrated this hadith except Abdullah bin al-Mu'ammal (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 563
Hadith Gradingمحدثین:فيه عبد الله بن المؤمل متكلم فيه، وبقية رجاله رجال الصحيح
Hadith Takhrij«قال الهيثمي: فيه عبد الله بن المؤمل وثقه ابن حبان وقال يخطئ وفيه كلام وبقية رجاله رجال الصحيح «مجمع الزوائد ومنبع الفوائد، ج 3، ص 242»» «أخرجه ابن خزيمة فى «صحيحه» برقم: 2737، والحاكم فى «المستدرك» برقم: 1687، وأحمد فى «مسنده» برقم: 7098»