Narrated Hudhayfah: The Prophet ﷺ said: Do not say: "What Allah wills and so and so wills, " but say: "What Allah wills and afterwards so and so wills.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
In the first sentence, associating others in Allah’s will (mashiyyah) is implied. This is impermissible and unlawful, for only that occurs which Allah alone wills. However, in the second sentence, if the will of others is mentioned with a distinction, then it is permissible.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4980