It is narrated from Sayyiduna Buraydah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "A stone that weighs as much as seven pregnant she-camels, if it is thrown into Hell, will keep falling in it for seventy years and still not reach its bottom."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Alqamah bin Marthad (may Allah have mercy on him) except Muhammad bin Aban (may Allah have mercy on him), and it is narrated from Sayyiduna Buraydah (may Allah be pleased with him) only with this chain."
Hadith Referenceالمعجم الأوسط / باب الميم / 5459
Hadith Gradingمحدثین:إسناده ضعيف لضعف محمد بن أبان الجعفي
Hadith Takhrij«قال الهيثمي: فيه محمد بن أبان الجعفي وهو ضعيف «مجمع الزوائد ومنبع الفوائد، ج 10، ص 389»» «أخرجه البزار فى «مسنده» برقم: 4459، والطبراني فى «الكبير» برقم: 1158»