It is narrated from Sayyida Aisha (may Allah be pleased with her) that when the Messenger of Allah (peace and blessings be upon him) intended to enter into Ihram, he would wash his head with khatmi herb and ushnan grass, and he would also apply some olive oil to his head.
Hadith Referenceالفتح الربانی / كتاب الحج والعمرة / 4156
Hadith Gradingمحدثین:ضعیف
Hadith Takhrij«اسناده ضعيف، عبد الله بن محمد بن عقيل ضعيفيعتبر به، ولم يتابع ھنا۔ أخرجه البزار: 1085، والدارقطني: 2/ 226، والطبراني في ’’الاوسط‘‘: 1172، (انظر مسند أحمد ترقيم الرسالة: 24490 ترقیم بيت الأفكار الدولية: 24995»
Brief Explanation
Benefits: … It is recommended (mustahabb) to perform a ritual bath (ghusl) at the time of assuming the state of ihram, as Sayyiduna Zayd ibn Thabit radi Allahu anhu narrates that the Messenger of Allah sallallahu alayhi wa sallam withdrew to a separate place in order to assume ihram and performed a ritual bath (ghusl). (Tirmidhi: 830)