for removing filth, the left hand is brought forward, while the right is reserved for everything else. On that basis, one performs istinjāʾ with the left hand and pours the water with the right, because the Prophet ﷺ forbade using the right hand for istinjāʾ. He ﷺ also said, “Nor should he wipe himself after relieving himself with his right hand,” meaning that the same rule applies when using stones for istijmār: if he wishes to wipe the place of defecation he must not hold the stone in his right hand; he holds it in his left.

Likewise, he ﷺ prohibited “breathing into the vessel.” When one drinks, the sunnah is to breathe three times: he drinks, pauses, drinks again, pauses, then drinks a third time. Such is the prophetic practice, and it is better for the body and gentler on the stomach. Thirst is an inflammation and heat inside the stomach; if water comes all at once it can harshly affect it, but if he sips it gradually, pausing to breathe three times, it is more soothing, more health-giving, and more pleasant, as the Prophet ﷺ stated. Yet when he breathes he must not breathe into the vessel; he should remove his mouth from it and then breathe. Breathing into the cup harms the drinker, for his breath rises while the water descends, they meet, and choking may occur. It also harms anyone who drinks after him, because diseases—what people now call microbes—exit with his breath, settle in the water, and may harm the next drinker. For that reason the Prophet ﷺ forbade a person to breathe into the vessel. Allah alone grants success.