Ownership (Hadith No. 1808)
Volume 3, Book 34, Number 313:
Narrated Abu Qatada (radiallaahu `anhu):
We set out with Allah’s Apostle (sallallaahu `alayhi wasallam) in the year of Hunain, (the Prophet gave me an armor). I sold that armor and bought a garden in the region of the tribe of Bani Salama and that was the first property I got after embracing Islam.
Once Prophet (sallallaahu `alayhi wasallam) gave the armor to Abu Qatada (radiallaahu `anhu), it became his. He had full rights over it so he could do whatever he wanted with it. He decided to sell it and get some property. This is perfectly permissible in this case.
What are your thoughts on the scenario if the armor he got was a gift and not from war booty? Would it be okay to sell it in order to buy some property like he did? Think about it.