Musnad Abu Ya'la al-Mawsili 117:139

'Abd al-Rahman ibn Salam narrated to us, Hammad narrated to us, from Thabit, from Anas, that Abu Talhah recited Surah Bara'ah. When he reached this verse: "Go forth, whether light or heavy," he said, "I see that my Lord is calling me to go forth, whether young or old. Prepare me." His sons said to him, "You have fought alongside the Messenger of Allah (peace be upon him) until he passed away, and you fought alongside Abu Bakr until he died, and you fought alongside 'Umar. So we will fight on your behalf." He said, "Prepare me." So they prepared him. He boarded the sea and died. They did not find an island to bury him in until seven days later, yet he had not changed.