Ibn Khuzaymah

Benefits:

➊ Using the left hand for istinja (cleaning oneself after relieving oneself) is included among the etiquettes of istinja, and there is consensus among the scholars on this issue that performing istinja with the right hand is a prohibited act. Then, the majority of scholars hold the view that this prohibition is one of dislike (tanzihi) and etiquette, not of being unlawful (haram), whereas some of the literalists (Ahl al-Zahir) are of the opinion that performing istinja with the right hand is haram. The position of our companions is that, without a valid excuse, using the right hand for any of the acts related to istinja is disliked (makruh). Thus, when performing istinja with water, the person should pour water with the right hand and clean with the left hand; and if performing istinja with a stone, then while cleaning the anus, one should use the left hand to clean with the stone. If cleaning the front private part (qubul) is intended, and it is possible to clean by placing the stone on the ground or between the feet, then one should hold the penis with the left hand and rub it on the stone; and if this is not possible, and it is necessary to pick up the stone to clean, then one should hold the stone in the right hand and, with the left hand, hold the penis and rub it on the stone, without moving the right hand. This is the preferred (rajih) method of istinja.

[نووي: 155/3]

➋ Holding the private part with the right hand is disliked (makruh tanzihi), not haram. «ولا يتنفس فى الاناء» When drinking water, one should not breathe into the vessel, and the well-known Sunnah is to take three breaths outside the vessel while drinking. The scholars explain that the prohibition of breathing into the vessel is an etiquette of drinking water, and this prohibition is due to the concern that it may cause the water to become foul-smelling, or that something from the mouth or nose may fall into the water while drinking.

[نووي: 159/3]