The Koran was compiled from Mohammad’s notes in approximately 650 AD nearly two decades after his death. And while Old Testament documentation was the starting point for the Koran and the religion of Islam, the Koran in its present form contains many teachings contrary to both Old and New Testaments. Originally Mohammad was very respectful of the Jews living in Arabia and he wanted them to join his movement. In fact, he even proclaimed that he was their prophet referred to in Deuteronomy.
“And the LORD said to me: ‘…I will raise up for them a Prophet like you from among their brethren, and will put My words in His mouth, and He shall speak to them all that I command Him. And it shall be that whoever will not hear My words, which He speaks in My name, I will require it of him.’” Deuteronomy 18: 17-19.
The Jews, however, knowing Mohammed descended from Ishmael and was furthermore not of the family of King David would not recognize him as their prophet and rejected his claims.
The New Testament subsequently confirmed that the Prophet announced in Deuteronomy was Jesus.
“Philip found Nathanael and said to him, ‘We have found Him of whom Moses in the law, and also the prophets, wrote – Jesus of Nazareth…’” John 1:45
“But those things which God foretold by the mouth of all His prophets…He has thus fulfilled. Repent…that He may send Jesus Christ, who was preached to you before…For Moses truly said to the fathers, ‘The LORD your God will raise up for you a Prophet like me from your brethren. Him you shall hear in all things, whatever He says to you. And it shall be that every soul who will not hear that Prophet shall be utterly destroyed from among the people.’” Acts 3:18-23
The Jews were given a stern warning not to presume to be a prophet if not called by God.
“But the prophet who presumes to speak a word in My name, which I have not commanded him to speak, or who speaks in the name of other gods, that prophet shall die.” Deuteronomy 18:20
History reveals that Mohammad was very zealous about the birth and development of Islam. He had become disenchanted with the polytheism that was growing in Arabia. He had a passion for monotheism and recognized it prevailed in Jewish scriptures which was a partial reason why he wanted the Jews to join him.
There are several Koranic references to the validity of the Old Testament Scriptures. Mohammed himself originally accepted their validity because he believed Allah had delivered the Pentateuch, Prophets, and the Psalms to the Jews. For example:
“And verily We (Allah) delivered the book of the law unto Moses; wherefore be not in doubt as to the revelation thereof; We ordained the same to be a direction unto the children of Israel.” Sura 32:23
“And verily We have bestowed favor upon some of the prophets more than upon others and We gave David the Psalms (Zabur). And We have given thee the Koran as We gave the Psalms unto David…” Sura 4:163
“And verily We have written in the Psalms after the promulgation of the law, that my servants the righteous shall inherit the earth, and in this Book are contained sufficient means of salvation unto people who serve God.” Sura 21:105
Inasmuch as the Old Testament was completed nearly 1,000 years before Mohammed’s birth and was originally validated by him, any differences between these Old Testament books and the Koran had to be attributed to Mohammed himself from his subsequent personal ‘revelations’ from Allah. The Bible states clearly that God and His word do not change.
“Of old You laid the foundation of the earth, and the heavens are the work of Your hands. They will perish, but You will endure; Yes, they will all grow old like a garment; like a cloak You will change them, and they will be changed. But You are the same…” Psalms 102:25-27
“For I am the LORD, I do not change…” Malachi 3:6
The Jews had another reason for not altering their own scared writings.
“Now, O Israel, listen to the statutes and the judgments which I teach you to observe…You shall not add to the word which I command you, nor take from it, that you may keep the commandments of the LORD your God which I command you.” Deuteronomy 4:1-2
Therefore, there remain major differences between the Old Testament and the Koran. Allah, the father of Adam and Abraham according to the Koran, is said to have given Mohammed new revelations nearly a millennium after the Old Testament was completed. The Biblical God of Adam and Abraham, however, is said to be unchanging.
For further study, Google ‘Islam and the Pentateuch’