[Edouard’s note: the story below was sent to me to Pure Man in Arabic, and is posted here under his name. Translation mine. It was first published a year ago, almost day for day and is being republished now]
These horses, al-Musinnat [plural form of Kuhaylat al-Musinn or al-Musinnah] are very ancient. They are from the horses of ‘Abdallah ibn ‘Abd al-Rahman ibn Faysal ibn Turki Aal Saud, the brother of King ‘Abd al-Aziz Aal Saud.
Prince Abd Allah, the brother of the king, had kept his horses in a private, separate farm. Upon his death, the horses went to his son, Prince Abd al-Rahman, and then to his grandson, Prince Faysal. And Prince Faysal is now aged. Then the horses went to Prince Turki Ibn Fahd Ibn Muhammad ibn Abd al-Rahman ibn Faysal ibn Turki, who is now preserving what remains from the asil horses, per God’s will.
Some of the Musinnat horses of Prince Abdallah, the brother of King Abd al-Aziz, participated in the Hedjaz campaign [i.e., the takover of the Hedjaz region from the Sharif of Mecca by the army of Ibn Saud in 1924].  Two men from Ibn Saud’s army fought particularly well in some episodes of this campaign: the first was Badi ibn Dhubyan from the tribe of Subay’, and he was riding a Musannan stallion that belonged to Prince Abdallah, the king’s brother. The second was Ibn Wareek, a Qahtan Bedouin from an ancient horsebreeding family.
Both fought pitched battles on horseback against one of the Sharif’s toughest warriors: Kharbush al-Dhuwaybi of the Harb tribe, who was riding a black stallion. Badi killed Kharbush in one of the battles, and the Sharif’s troops and Bedouin auxiliaries were defeated.