Khalid bin al-Harith bin 'Ubaid خالد بن الحارث بن عبيد · The Chapters on Jihad

“May Allah have mercy on the one who keeps watch over the troops.”

“I saw a man asking my father about a man who goes out to fight and buys and sells and trades during his campaign. My father said to him: ‘We were with the Messenger of Allah (ﷺ) in Tabuk, and we bought and sold, and he saw us and did not forbid us (to do that).’”