Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "If a stone were thrown into Hell, it would keep falling for seventy years before reaching its bottom."
Abu Ya'la recorded it, and al-Bazzar recorded something similar. The chain of both contains a narrator, Ata' bin al-Sa'ib, who suffered from confusion (ikhtilat) in his memory; the remaining narrators of both are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب صفة أهل النار / 18588
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه البزار فى المسند (3494) اخرجه ابو يعلى فى المسند (7243) ، أخرجه صحيح ابن حبان برقم: 7468»