It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that he (peace and blessings be upon him) said: "Do not say: 'Whatever Allah wills and so-and-so wills,' but rather say: 'Whatever Allah wills, then whatever so-and-so wills.'"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5810