"Then Hilkiah the high priest said to Shaphan the scribe, "I have found the book of the law in the house of the Lord." And Hilkiah gave the book to Shaphan who read it." 2 Kings 22:8
The Hebrew text was written down for ages. It was translated into Greek in about 200-400 BC for easy reading by the populace who by this time spoke Greek. However, because of the differences in language, some of the word meanings did not translate easily. (Like translating Greek to English.)
The quotes used by the apostles in the New Testament either used the Hebrew text, the Greek text, or as was common among Jewish scholars, quoted the Greek scriptures with commentary to add clarification to the text. That is why if you compare some of the NT quotes against OT quotes there is not always a one-for-one correspondence.