When the Messenger of Allah ﷺ intended to enter the state of ihram, he would wash his head with marshmallow leaves and potash, then anoint it with a small amount of oil.
كان رسول الله ﷺ إذا أراد أن يحرم غسل رأسه بخطمي وأشنان، ودهنه بشيء من زيت غير كثير.
Ahmad (24490), Bazzar - Kashf Astar (1085), and Daraqutni (2451) all narrated it from the hadith of Zakariya bin Adi, who said, Ubaydullah bin Amr narrated to us, from Abdullah bin Muhammad bin Aqeel, from Urwa, from Ayesha, and he mentioned it. The wording is that of Bazzar and Daraqutni. As for Ahmad, he mentioned in it the story of her performing umrah from Tanim.Its chain is hasan due to the discussion regarding Abdullah bin Muhammad bin Aqeel, except that his hadith is hasan, as has been explained in detail many times before.