The Messenger of Allah ﷺ forbade cauterization. He disliked drinking very hot water. When he applied kohl, he applied it an odd number of times, and when he cleaned himself with stones, he used an odd number of stones.
نهى رسول الله ﷺ عن الكي، وكان يكره شرب الحميم، وكان إذا اكتحل اكتحل وترا، وإذا استجمر استجمر وترا.
Ahmad narrated it (17426) from Hasan, who said, Ibn Lahia narrated to us, Harith bin Yazid narrated to us, from Abdul-Rahman bin Jubayr, from Uqba bin Amir, and he mentioned it. He also narrated it through other routes from Ibn Lahia (17427, 17428). Tabarani narrated it in Al-Kabir (4/93) through another route from Abu Abdul-Rahman Muqri, from Ibn Lahia with his chain, in abridged form.The narration of Muqri is more reliable than the others, and it strengthens what came before. It shows that Ibn Lahia did not err in this hadith, and with this the hadith becomes hasan.His saying, "apply kohl in odd numbers," can be understood in two ways. The first is that one should apply kohl an odd number of times to each eye. The second is that the total application of kohl to both eyes together should be odd, as in the hadith of Anas.