Musnad Ahmad 258:8

Ibrahim ibn Ishaq narrated to us, he said: Damrah ibn Rabi'ah narrated to us, from Ibrahim ibn Abi 'Ablah, from al-Ghurayf al-Daylami, he said: We came to Wathilah ibn al-Asqa' al-Laythi, and we said: "Narrate to us a hadith you heard from the Messenger of Allah, may Allah bless him and grant him peace." He said: "We came to the Prophet, may Allah bless him and grant him peace, regarding a companion of ours who had become deserving [of the Fire]. He said: 'Free [a slave] on his behalf, and Allah the Mighty and Majestic will free for every limb of his, a limb of his from the Fire.'"