"Is the Sunnah to use the siwak with the right hand or the left? And what is the evidence for that? "

"No authentic hadith from the Prophet, peace and blessings be upon him, has been reported concerning with which hand to use the siwak. The jurists have differed in their opinions regarding this. Some have said to use the right hand because the siwak is a Sunnah, while others have said to use the left hand because it is a form of removing harm, and this is the well-known position of the Hanbali school. Some Malikis have distinguished between purifying the mouth and attaining the Sunnah. Sheikh Ibn Uthaymeen, may Allah have mercy on him, believed that the matter is broad due to the lack of clear textual evidence, and the Sunnah has been reported as starting with the right side of the mouth.

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