Ata' (may Allah have mercy on him) said: A man pledged a horse and it died. He (peace and blessings be upon him) said: "The pledge is in exchange for what is in it." Zam'ah bin Salih narrated this hadith with the same wording from Ibn Tawus, from his father, as mursal, but without the story, and Zam'ah is not strong. Imam al-Shafi'i (may Allah have mercy on him) said: In this issue the mursal of Sa'id bin al-Musayyib (may Allah have mercy on him) is accepted, because his mursal reports are stronger than the mursal reports of others, and also because this report has been narrated as connected (mawsul).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الرهن / 11226