Musannaf Ibn Abi Shayba 3:3519

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Isma’il narrated to us, from Abu Ishaq, from Arqam ibn Sharhabil, from Ibn Abbas: That when the Prophet, peace and blessings of Allah be upon him, came to Abu Bakr while he was in prayer during his illness, he began the recitation from where Abu Bakr had reached.