ANSWER:

No, this does not invalidate the prayer as this is not mandatory, rather its a highly recommended Sunnah.

While am praying in the Masjid at times the person next to me doesn’t stretch his legs in order to close the gap in order to prevent shayateen to enter no matter… Does this invalidate the prayer?

Prayer | May 17, 2019 2:47 am
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In silent Rakah behind an Imam, what should I do if I am in the middle of a long Ayah and the Imam goes to Rukoo? Should I just interrupt the recitation and then join him?