«إذا حلف أحدكم فلا يقل ما شاء الله وشئت ولكن ليقل ما شاء الله ثم شئت»
The Prophet (peace and blessings be upon him) said:
"When one of you swears an oath (or states something with certainty), let him not say: 'What Allah willed and you willed,' but rather let him say: 'What Allah willed, then what you willed.'"
Hadith Referenceصحیح الجامع الصغیر / حرف الألف / 495