Do not swear false oaths; do not use deception or trickery when dealing with others; be honest; be truthful; practice justice and fairness when dealing with others.

This hadith talks about the consequences of taking an oath to take someone else's property by unfair means. It was narrated by Abdullah ibn Mas'ud who said that the Messenger of Allah said that whoever swears an oath in which he tells a lie to take the property of a Muslim by unfair means will meet Allah while He is angry with him. Al-Ash'ath swore that this was said about him as there was some land between him and a Jew but he denied it to him so he presented his case to the Prophet. The Prophet asked for evidence and Al-Ash'ath replied that he asked for an oath from the Jew but feared that if he took it then his property would be taken away from him. As a result, Allah revealed a verse in which He warned against selling one's faith for a small price and promised them no portion in the hereafter if they did so. This hadith teaches us not only not to swear false oaths but also not to use any kind of deception or trickery when dealing with others as it can have serious consequences both in this world and in the hereafter.