In The Name of Allaah, The Most Merciful, The Bestower of Mercy

Al-Baraa’a [radiyallaahu anhu] said:
When we prayed behind the Messenger [sallal laahu alayhi wasallam], we liked to be on his right..
[Saheeh Muslim’ Number 1642]

Shaikh Abdul Muhsin Al-Abbaad [hafidhahullaah] said: Al- Haafidh Ibn Hajar [rahimahullaah] said in Al-Fath 1/270: This hadeeth is utilised as proof to show that it is desired that one prays on the right of the Imaam – in the right side of the Masjid [i.e. on the right whilst praying behind the Imaam].

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Source: ‘Sharh Aadaabul Mashee Ilas Salaah’  in the Shaikh Majmoo’ah titled: Kutub Wa Rasaa’il Abdul Muhsin Bin Hamad Al-Abbaad Al-Badr. Vol 5. page 129