Generally speaking  you have to fight it, if not, at least you must cover your mouth with your hand.

Should we put hand against mouth when we yawn? Is this Sunnah?

Prayer | June 1, 2016 9:26 am
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Can we recite in Salah after Surah Fatiha .Rabbi auzini ash kurallati an amta alaiya wali walidaiya wa. an saliheen. ……ending the ayat up to. minal. muslimeen?