"You have heard that it was said" (5:21). Is everything Jesus quotes in these sayings in the Old Testament?

Not all of it word for word, and Jesus doesn't say where any of it was said. Some of his words are in the law in the WEB: "You shall not murder" (Exodus 20:13), "You shall not commit adultery" (Exodus 20:14), and "you shall love your neighbor as yourself" (Leviticus 19:18). Some are in the law in other words: "An eye for an eye, and a tooth for a tooth" (5:38) beside "eye for eye, tooth for tooth" (Exodus 21:24), and "perform to the Lord your vows" (5:33) beside "When a man vows a vow to the LORD, or swears an oath to bind his soul with a bond, he shall not break his word" (Numbers 30:2). The saying in 5:31 is set beside the law's words in the section Divorce, beside Mark 10. Here is what almost everyone misses: the words of three phrases Jesus gives are in no verse of the WEB's Old Testament: "Whoever murders will be in danger of the judgment" (5:21), "You shall not make false vows" (5:33), and "hate your enemy" (5:43). Jesus says only that "it was said", and twice that it was said "to the ancient ones" (5:21, 5:33). He doesn't say who said them, and these notes don't either.