What is the proper manner of using the Siwak?

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The Siwak must be used on both the teeth and the tongue. Abu Musa reported seeing the Prophet using it on his tongue. The Siwak should be used crosswise (horizontally) across the teeth, not lengthwise, because using it lengthwise from the edges to the root might cause gum bleeding and damage the tooth structure. Furthermore, initiating the cleaning with the right side (tiyaman) is recommended, following the general practice of the Prophet in all matters such as putting on shoes, combing hair, and purification.