“Whoever says that offering prayers with unfolded hands is a custom related to Shi’as, that person is at fault in this regard, because not only the Shi’as but the whole Muslim Ummah offered the prayers in the same way, especially during the life time of Holy Prophet (s) the companions did it the same way and no one knew about the folding of hands.”
Sunni reference: Hadiyatul Mahdi, by Maulana Waheed uz Zaman, Volume1, page 126
The Holy Prophet (s) and his companions used to offer prayers with unfolded hands to the extent that their finger tips got red due to the blood getting blocked there.
Sunni reference: Imam of Ahl’ul Sunnah Ai’ni in Sharh Kunz ul Daqaiq, page 250, published in Nolakshoor
“Imam ibn e Qasim reports Imam Malik offered prayers without folding hands.”
Sunni reference: Fathul Bari fee Sharh Sahih al Bukhari Volume 2 page 224
“The Fatawa of Imam Malik is well known, namely that he would pray with open hands”
Sunni reference: Sherani in Meezan al Kubra Volume 1 page 150, Dhikr Salath
“Ibn Qasim recorded Imam Malik’s reading with open hands in Salat, and the vast bulk of Maliki Ulema have embraced this Fatwa, and they deem closing the arms to be Makruh, Ibn Hajaab said that folding of the arms should be restricted to ease”.
Sunni reference: Fathul Bari fee Sharh Sahih al Bukhari Volume 1 page 324
“Auzai said that closing or opening the hands is within one’s choice, the option of folding is to make life easier, as lenthy recitals would often lead blood rushing to the finger tips of the Sahaba”
Sunni reference: Kifaya Sharh Hidayah Volume 1 page 250
“Imam Malik issued a Fatwa that the arms should remain open during Salat, if recitals are long then for the purposes of ease the arms can be folded”
Sunni reference: Umdah thul Qaree fee Sharh Sahih al Bukhari Volume 3 page 5