There is no harm in this, and this is the opinion of al-Shafi'i. Abu Yusuf said: It is not permissible to endow animals, slaves, horses (al-kura'), trade goods, weapons, young boys, cattle, or equipment in endowed land as an accessory to it; because [this is an animal] that is not fought upon, so it is not permissible to endow it, just as if the endowment were for a limited period. From Malik, there are two narrations regarding horses and weapons. Our evidence is that the Prophet - may Allah bless him and grant him peace - said: "As for Khalid, he has tethered his coats of mail and his gear (a'tadahu) in the cause of Allah." Agreed upon. In another narration: "And his equipment (a'tudahu)." It was recorded by al-Bukhari. Al-Khattabi said: The 'a'tad' (gear) is what a man prepares from [mounts, weapons,] and the equipment of Jihad. It was narrated that Umm Ma'qil came to the Prophet - may Allah bless him and grant him peace - and said: "O Messenger of Allah, Abu Ma'qil has dedicated his water-carrying camel in the cause of Allah, and I intend to perform Hajj; may I ride it?" The Messenger of Allah - may Allah bless him and grant him peace - said: "Ride it, for Hajj and 'Umrah are from the cause of Allah." Furthermore, because it results in the tying up of the principal and making the benefit available, its endowment is valid, like real estate [and a tethered horse. And because it is valid to endow it along with other things, it is valid to endow it alone, like real estate].