To be the slave of Allah was the best Mohammad could hope for.
To be the slave of Mohammad was the best a Mulism could hope for...
To be the slave of a Muslim is the best a Dhimmi (infidel)
can hope for...
Freedom from the will of Allah aka the will of Allah aka the will of Islam is slavery to evil...
Only slavery to the will of Allah,the will of Mohammade,and the will of Islam is true freedom...
To be perfectly fair, both the Old and New Testament consistently refer to believers as slaves of God.