Is the fast of a disbeliever valid?

For an act of worship (ibadah) to be valid, Islam is a prerequisite. Worship is not valid from a disbeliever because it lacks intention, and the disbeliever is not qualified for it, as affirmed by the Almighty’s saying: "And whoever disbelieves in faith—then his work has become worthless, and in the Hereafter he will be among the losers." Fasting is an act of worship that is not valid from a disbeliever, by agreement of the scholars. It is obligatory upon the Muslim, not the disbeliever, because it is a purely physical act of worship that requires Islam and intention. Disbelief prevents the validity of fasting by consensus.