The Messenger of Allah ﷺ said, "By Allah, it is not I who give you, nor I who withhold from you. I am only a distributor, placing it where I am commanded."
Ahmad 10257
Sahih
وبهذا الإسناد قال قال رسول الله ﷺ والله ما أعطيكم ولا أمنعكم وإنما أنا قاسم أضعه حيث أمرت
Its isnad is sahih. Bukhari narrated it in the chapter on the obligation of the khums, regarding the words of Allah Almighty, "then a fifth of it belongs to Allah" [Anfal 8:41], with a similar wording.