It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever takes the right of a Muslim by (false) oath, Allah Almighty has made Hell obligatory for him and Paradise forbidden for him." This companion asked: "Even if it is a small thing?" He replied: "Even if it is only a twig of the Salvadora (peelu) tree."
Swearing a false oath is, in itself, a grave sin. Then, to swear a false oath and usurp someone’s wealth is an even greater sin, and there is no restriction in this matter regarding whether the person is a Muslim or a non-Muslim. Although in this hadith, the obligation of Hell and the prohibition of Paradise are mentioned in connection with the wealth of a Muslim, this ruling is general: to unlawfully and unjustly seize anyone’s wealth is forbidden, and to usurp the wealth of one’s Muslim brother is an even greater sin. No specific limit has been set for this wealth; rather, even if it is a small thing, to take it or seize it is forbidden.