'When anyone of you swears an oath, let him not say: 'What Allah wills and what you will.' Rather let him say: 'What Allah wills and then what you will.' (Using translation from Ibn Mājah 2117)
"إِذا حَلفَ أحدُكُمْ فلا يَقُلْ: ما شاء اللهُ وشِئتُ ولكن ليقُلْ: ما شَاءَ اللهُ ثم شِئْتُه".