Ok. For now just to keep it brief I will mention one prophecy Only.
It is well known among the Arabs that Muhammad was a descendent of Ishmael. You can research this yourself in more depth.
Ancestry of Prophet Muhammad
Prophet Muhammad belonged to the generation of Prophet Ishmael (Ismail) , usually called Banu Ismail (Children of Ishmael). One of the sons of Prophet Ishmael was Qaidar (Kedar), in whose progeny a man named Adnan emerged to prominence, who was the ancestor of Adnanites tribes of Arabia.
6 Prophet Muhammad belonged to the Quraysh branch of Adnanites.
Genesis 17:20
20 And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly; twelve princes shall he beget, and I will make him a great nation.
Muhammad was a descendant of Ishmael and the twelve princes were spiritual princes which we believe are the Twelve Imams and the great nation a spiritual nation is we believe to be Islam. So the Shiah sect of Islam which was descended from the Prophet is considered true Islam.
Now we are told that there are about 72 meanings in the scriptures and humanity is only aware of maybe one so although the above verse may be interpreted with other legitimate meanings, we believe one of the meanings is referring to Muhammad and the Twelve Imams.
There are many more scriptures which even more cogently refer to Muhammad and Islam but one needs to know a little about the history of Islam to understand.