Musannaf Ibn Abi Shaybah

Hazrat Khalid bin Abi Imran (may Allah have mercy on him) says that I asked Hazrat Qasim bin Muhammad (may Allah have mercy on him) and Hazrat Salim bin Abdullah (may Allah have mercy on him), both of them: We have a slave who works as a potter in the enemy's territory. Then he sells those pots and accumulates a considerable amount of wealth, and he also spends from it on us. They replied: There is no harm in this.

Hazrat Khalid bin Abi Imran (may Allah have mercy on him) says that I asked Hazrat Qasim bin Muhammad (may Allah have mercy on him) and Hazrat Salim bin Abdullah (may Allah be pleased with them both): One of us is in the land of the enemy, so he hunts fish and sells them. Then he accumulates a lot of dirhams. What is the ruling regarding this? He (may Allah have mercy on him) replied: There is no harm in it.