What is the ruling on yawning during prayer, and is it obligatory to place the right hand over the mouth when yawning to prevent Satan from entering?

Regarding placing the hand over the mouth when yawning, it is recommended both during prayer and outside of it. The hadith did not specify the right hand, but some scholars mentioned that the left hand is more appropriate because it is used to remove harm. The Malikis disliked covering the mouth with the palm of the left hand, preferring to use the back of it, or the right hand, whether with its back or palm. All of this is by way of recommendation and preference, and what is required is to cover the mouth when yawning.