"Whoever swears an oath and says, 'If Allah wills,' then he has the choice: If he wishes, he may go ahead, and if he wishes he may not."
عَنِ النَّبِيِّ ﷺ قَالَ مَنْ حَلَفَ عَلَى يَمِينٍ فَقَالَ إِنْ شَاءَ اللَّهُ فَهُوَ بِالْخِيَارِ إِنْ شَاءَ أَمْضَى وَإِنْ شَاءَ تَرَكَ