[Machine] The Prophet ﷺ said: "When you wash (while performing ablution), take (use) the toothstick (miswak) and leave a third (of the mouth unwashed). But if you do not use the toothstick, then leave a quarter (of the mouth unwashed)."  

أَنَّ النَّبِيَّ ﷺ قَالَ «إِذَا خَرَصْتُمْ فَخُذُوا وَدَعُوا دَعُوا الثُّلُثَ فَإِنْ لَمْ تَدَعُوا الثُّلُثَ فَدَعُوا الرُّبُعَ»