أَبُو أُمَامَةَ بْنُ ثَعْلَبَةَ الْأَنْصَارِيُّ، عَنْ عَبْدِ اللهِ بْنِ أُنَيْسٍ
[Machine] The Messenger of Allah, ﷺ , said: "The greatest of major sins are associating partners with Allah, disobedience to parents, false oath, and to swear by the moon. By the One who holds my life in His hand, no one swears an oath, even if it is as small as the wing of a gnat, except that it leaves a mark on his heart until the Day of Resurrection."
قَالَ رَسُولُ اللهِ ﷺ «أَكْبَرُ الْكَبَائِرِ الْإِشْرَاكُ بِاللهِ وَعُقُوقُ الْوَالِدَيْنِ وَيَمِينُ الْغَمُوسِ وَايْمُ الَّذِي نَفْسِي بِيَدِهِ لَا يَحْلِفُ أَحَدٌ وَإِنْ كَانَ عَلَى مِثْلِ جَنَاحِ بَعُوضَةٍ إِلَّا كَانَتْ وَكْتَةً فِي قَلْبِهِ إِلَى يَوْمِ الْقِيَامَةِ»