Zaid Alsalami, Shaykh Dr Zaid Alsalami is an Iraqi born scholar, raised in Australia. He obtained a BA from Al-Mustafa University, Qom, and an MA from the Islamic College in London. He also obtained a PhD from... Answered 1 year ago
Bismihi ta'ala
We pray as the holy Prophet (s.a.w.) prayed, and he did not fold his arms during his prayer. This is something even Sunni scholars acknowledge. Sunni Malikis also do not fold their arms in salat.
Ahlul Bayt (a.s.) were the closest to the Prophet (s.a.w.), and in the Ja'fari jurisprudence, hands must be to the side, as did the Prophet (s.a.w.).
For this reason, it is haram to legislate anything not a part of the shari'ah, which means that folding of arms would be haram and the prayer would be invalid.
This is the common view of Shi'i jurists.
And Allah knows best.