Answered by Shaykh Faraz Rabbani
How important is it for the Muslim to sit in iftirash style in the prayer? If it causes him difficulty and distracts him from concentrating on his prayer does he lose out on any reward from Allah (swt)?
Answer:
Walaikum assalam wa rahmatullahm
I pray that this finds you well, and in the best of health and spirits. May Allah grant you all good and success in this life and the next.
One should strive to sit this way. However, if it is physically difficult, then one may adjust one’s position (ideally, as close to the sunna sitting as possible) such that one can pray with focus and concentration.
And Allah alone gives success. Faraz Rabbani