وَعَنِ ابْنِ عُمَرَ
أَنَّ رَسُولَ اللَّهِ صَلَّى الله ليه وَسَلَّمَ قَالَ: «مَنْ حَلَفَ عَلَى يَمِينٍ فَقَالَ: إِنْ شَاءَ اللَّهُ فَلَا حِنْثَ عَلَيْهِ»
Ibn Umar reported God’s Messenger as stating that if anyone says when swearing an oath, “If God will”, he is not held accountable if he breaks it. Tirmidhi, Abu Dawud, Nasai.
Mishkat al-Masabih 3291, Book 16, Oaths and Vows, Hadith 19. 1 min read