Sayyidah Aishah (may Allah be pleased with her) says: Some people say that Sayyiduna Abu Bakr (may Allah be pleased with him) was ahead of the Prophet (peace and blessings be upon him) in the row, and some people say that the Prophet (peace and blessings be upon him) was ahead.
This is how al-Tayalisi narrated it from Shu'bah from al-A'mash, whereas the narration of the majority from al-A'mash, as given above, is the established and authentic one. As for the narration of Masruq, only Nu'aym bin Abi Hind narrated it, from Abu Wa'il from him, and there is disagreement over it from him.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5084