The Messenger of Allah ﷺ said, "When one of you performs ablution, let him draw water into his nose and then expel it." On another occasion he said, "Let him blow it out."
حدثنا سفيان حدثنا أبو الزناد عن الأعرج
قال رسول الله ﷺ إذا توضأ أحدكم فليجعل في أنفه ثم ليستنثر وقال مرة لينثر
Its isnad is sahih. Muslim related it, 1:83, along with the command to perform istinja, through the route of Sufyan bin Uyayna, with this same isnad. Bukhari related it likewise, 1:229-231, and added along with it the previous hadith, 2780, all of these through the route of Malik from Abu Zinad. The command to perform istinthar and istinja is found in the Muwatta, 19, from Abu Zinad, and see what has passed at 7220.As for his saying, "let him put in his nose," he means water, and what is established in the source texts here is that "water" is omitted. Likewise, the transmitters of the Muwatta and the transmitters of Bukhari differ over whether it is included or omitted, as the Hafiz noted in Fath al-Bari.As for his saying in the other version, "let him blow out," this is how it appears in H and K, while in M it appears as "let him blow himself out," with an extra letter ta inserted between the nun and the tha, and the mark of soundness was written above it. Both versions are established among the transmitters of Bukhari and the transmitters of the Muwatta as well.The Hafiz said, Farra said, one says nathara the man, and antathara, and istanthara, when he moves the nuthra, which is the tip of the nose, during purification.