Covering the mouth when yawning in Salah

Q: I am a religious young man and I perform the five daily obligatory Salahs (Prayers) on their due times. All praise is due to Allah that He helps me to do so. My question now is: I usually suffer from yawning during Salah, so I have to place my hand on my mouth in order not to harm my Muslim brother who is offering Salah beside me. Since I know that frequent movements nullify Salah, could you kindly enlighten me how to get rid of this habit which bothers me and those around me? May Allah reward you.

A: Seek refuge in Allah against the cursed Satan after saying Takbirat Al-Ihram (The opening takbir for commencing Salah by uttering "Allahu-Akbar" Allah is the Greatest) and after saying Al-Istiftah (The invocation said after Takbirat Al-Ihram) and before reciting Surah Al-Fatihah. Reflect on the Qur'an which is recited in Salah. Call for the reverence of your Lord in your heart during bowing and prostration. Supplicate to Allah in your prostration with submissiveness to Him to stop the insinuations of Satan and to protect you from his trials. (Part No. 7; Page No. 39) When you do this, Allah will help you and ward off the laziness that you complain of. He will grant you activity in worship, a clear mind and submissiveness by His might and strength. Placing your hand on your mouth to block yawning is an act of Sunnah but try to close your mouth while yawning as much as you can as the Prophet (peace be upon him) commanded. May Allah protect and maintain you in your worship and in all the good acts that you do. May Allah accept worship from you and us!May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.