Musannaf Ibn Abi Shayba 28:472

Mu'tamir ibn Sulayman narrated to us, from Abu al-Munayya, who said: A man from the people of al-Yamama bequeathed a horse in the way of Allah. My cousin came, and I said, "I will mount my brother upon it, for my brother is a righteous man." He said, "Wait until I ask al-Hasan." So he asked al-Hasan, and he said, "Mount a man upon it, and do not fear anyone regarding it." He said: I said to al-Hasan, "What if he is in need of it?" He said, "Then let him sell it to the soldiers, and do not give it to these clients (mawali), lest one of them leave it as an expenditure for his family."