Tahafut_al-Tahafut-transl-Engl-van-den-Bergh

discovered that the present individual is produced through the corruption
of its predecessor and that the corruption of this previous individual
implies the production of the one that follows it, and that it is necessary
that this everlasting change should proceed from an eternal mover and an
eternal moved body, which does not change in its substance, but which
changes only in place so far as concerns its parts, and approaches certain
of the transitory things and recedes from certain of them, and this is the
cause of the corruption of one half of them and the production of the other
half. And this heavenly body is the being that changes in place only, not in
any of the other kinds of change, and is through its temporal activities the
cause of all things temporal; and because of the continuity of its activities
which have neither beginning nor end, it proceeds from a cause which has
neither beginning nor end. The second reason why they introduce an
eternal being absolutely without body and matter is that they found that all
the kinds of movement depend on spatial movement, and that spatial
movement depends on a being moved essentially by a prime mover,
absolutely unmoved, both essentially and accidentally, for otherwise there
would exist at the same time an infinite number of moved movers, and this
is impossible. And it is necessary that this first mover should be eternal, or
else it would not be the first. Every movement, therefore, depends on this
mover and its setting in motion essentially, not accidentally. And this
mover exists simultaneously with each thing moved, at the time of its
motion, for a mover existing before the thing moved-such as a man
producing a man-sets only in motion accidentally, not essentially; but the
mover who is the condition of man’s existence from the beginning of his
production till its end, or rather from the beginning of his existence till its
end, is the prime mover. And likewise his existence is the condition for the
existence of all beings and the preservation- of heaven and earth and all
that is between them. All this is not proved here apodictically, but only in
the way we follow here and which is in any case more plausible for an
impartial reader than the arguments of our opponents.
If this is clear to you, you certainly are in no need of the subterfuge by
which Ghazali in his argument against the philosophers tries to conciliate
them with their adversaries in this matter; indeed these artifices will not do,
for if you have not understood how the philosophers introduce an eternal
being into reality, you have not understood how they settle the difficulty of
the rise of the temporal out of the eternal; they do that, as we said, either
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