Abomination of saying: “What Allah Wills and so-and-so Wills”

Imam Al-Nawawi’s Riyad-us-Saliheen
Chapter 333
Abomination of saying: “What Allah Wills and so-and-so Wills”

1745. Hudhaifah bin Yaman (May Allah be pleased with him) said: The Prophet (sallallaahu ’alayhi wa sallam) said, “Say not: `What Allah wills and so-and-so wills’, but say: `What Allah wills, and then what so-and-so wills.”’
[Abu Dawud with authentic Isnad].