Uqayl narrated that Ma'bad bin Ka'b said that his brother, Abdullah bin Ka'b bin Malik, told him that he heard Sayyiduna Abu Umamah al-Harithi (may Allah be pleased with him) say: I heard the Messenger of Allah (peace and blessings be upon him) say: "No man seizes the right of a Muslim by means of his oath except that Allah forbids Paradise to him and makes Hell obligatory for him." A man from among the people said: O Messenger of Allah, even if it is something small? He (peace and blessings be upon him) said: "Even if it is a tooth-stick (miswak) of the arak tree."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 796