When the Messenger of Allah ﷺ fell ill, he ordered Abu Bakr to lead the people in prayer. Then he felt some relief and went out. When Abu Bakr sensed his presence, he wanted to step back, but the Prophet ﷺ gestured to him to remain. The Prophet ﷺ sat down beside Abu Bakr on his left and continued the recitation from the verse where Abu Bakr had stopped.
حدثنا يحيى بن زكريا بن أبي زائدة حدثني أبي عن أبي إسحاق عن الأرقم بن شرحبيل
لما مرض رسول الله ﷺ أمر أبا بكر أن يصلي بالناس ثم وجد خفة فخرج فلما أحس به أبو بكر أراد أن ينكص فأومأ إليه النبي ﷺ فجلس إلى جنب أبي بكر عن يساره واستفتح من الآية التي انتهى إليها أبو بكر
Its isnad is sahih. Zakariya bin Abu Zaida is trustworthy. Ahmad gave preference to his narrations from Abu Ishaq Sabi over the narrations of Israil when they differed, and Bukhari gave his biography in al-Kabir, 2/1, 196-197. Ibn Kathir transmitted this hadith in al-Tarikh, 5:234, from this same place. It will come again, both abridged and in full, from Waki from Israil from Abu Ishaq, at 3330 and 3355. Ibn Saad also reported it in abridged form, 3/1/130, from Waki, and Ibn Majah reported it, 1:193, in full, by way of Israil, and likewise Bayhaqi, 3:81. Something similar to it has already passed, both in full and abridged, by way of Abdullah bin Abu Safar from Arqam bin Shurahbil from Ibn Abbas from his father Abbas, at 1784 and 1875.The most that can be said is that Ibn Abbas narrated it from his father, sometimes mentioning his father and sometimes narrating it without mentioning him, making it a mursal narration of a companion, which is sahih in either case. See Nasb Raya, 2:50-52, and see 1784 and 1785.