Alan Gardiner explains phrase "in the hand of" in ancient Egyptian.
Alan Gardiner, Egyptian Grammar, 3rd ed. (Oxford: Griffith Institute, 1957), §178
m-Ꜥ, lit. 'in the hand of' is common in various meanings.
I. 'together with' a person (like ḥnꜤ). X came m-Ꜥ Y 'with Y' . . .
2. 'in the possession, charge of' . . .
3. 'from': a letter 'from' a person; bring something 'from' someone . . .
4. 'through,' 'because of' someone or something: ḫpr m-Ꜥ 'happen through' i.e. 'be done by' . . .