Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 2 years ago

The habit of folding ( crossing) 

hands during Salaah came from non-Muslims (notably Zoroastrians) and wasn’t part of the Salaah of the Holy Prophet (sawa), nor during the government of Abu Baker. However, during the rule of Umer ibn Khattab, when Persia was concurred by Muslims, several prisoners of war were brought from Persia to Madina. They folded their hands in front of Umer, who asked them why they did so. They responded that it was their habit in front of respected people. Umer liked it and decided to keep it in the prayer. Ali ibn Abi Talib (a.s) and many of the Sahaba refused this, because no one has the right to change or add or to omit anything from the Salaah, and the Prophet (sawa) had famously said, “Pray as you saw me praying.
Therefore Amir ul Mo’mineen (a.s), his followers (Ammar ibn Yasir, Salman al Farsi, Abu Dhar al Ghifari) and all of his other pious companions continued opening their hands while praying, exactly like the Prophet (s) used to. 
In the Sunni school of thought, none of the four leading jurists (Abu Hanifa, Shafi’i, Malik ibn Anas, Ahmad ibn Hanbal) ever said that it was obligatory to fold hands during Salaah, because there was no evidence to support it. Imam Malik even said it was not good to fold hands, and all Malikis thus open their hands in Salaah. A famous Sunni ‘Aalim from Egypt, Sayyid Sabiq, wrote in his book Fiqh as Sunnah: “we do not have even a single authentic Hadith that the Prophet (s) ever folded his hands in the Salaah.
 Numerous famous individuals from the Sunni school of thought such as Abdullah ibn Zubayr and Laith bin Saad didn’t fold their hands either. Folding hands in Salaah was therefore not part of Islam, it was brought to Muslims from non Muslims by Umer ibn Khattab.