Imam al-Sâbûnî [d. 449 AH] – “The scholars of hadith confirmed the validity of Abu Bakr’s appointment as caliph after the death of the Messenger of Allaah ﷺ, because he was chosen by the Sahaabah (Companions).
They unanimously agreed on that, and they said: The Messenger of Allaah ﷺ was content with Abu Bakr leading us in our religious matters (prayers), therefore we are pleased for him to lead us in our worldly matters. In other words, the Prophet ﷺ appointed him to lead the people in the obligatory prayers when he was sick, which is their religious affairs, so we accept him as the successor of the Messenger ﷺ with regard to our worldly affairs.”
→ ‘Aqidatul Salaf wa As-haab-ul-Hadith – Pg. 290 | Imam Abu ‘Uthman al-Sâbûnî [Edition: Dar al-‘Aasimah] | Translated by: Abu Dawūd [Mustafa b. Saalih] al-Hushayshi