Is it true that Imam Ali (as) is referred to as Khayr al-Bashar instead of Prophet Muhammad (pbuh)? If so, what is the reason for it considering that Prophet Muhammad (pbuh) holds a higher status than Imam Ali (as)?
The fact that Ali is the best of human beings (Khairul Bashar) means the best of all human beings after the Prophet Muhammad (SAWA) and it never means that Ali is better than the Prophet Muhammad at all. This Hadeeth has been narrated many well known Sunni books like:
1. Musnad Ahmed Bin Hanbal, Fadha;I'll al-Sahabah, Hadeeth number 917 and 1110 and 177.
2. Mussannaf Ibn Abi Shaibah مُصَنَّف ابن أبي شيبة number 31503.
3. Kanzul Ummal, V.11, page 625.
4. Ibn Asaakir in Tareekh Dimishq , V. 24, page 372.
5. Al-Qandoozi Al-Hanafi in Yanaabee'ul Mawaddah , V.2, page 78.
Ali (AS) is the best of the Ummah of the Proohet Muhammad (SAWA).
Wassalam.