Is the Sermon on the Mount based on Leviticus?

Question

In Leviticus 19:17 (NASB)

‘You shall not hate your fellow countryman in your heart; you may certainly rebuke your neighbor, but you are not to incur sin because of him.

Then in Matthew 5:22 (NASB)

But I say to you that everyone who is angry with his brother shall be answerable to (the court; and whoever says to his brother, ‘You good-for-nothing,’ shall be answerable to the supreme court; and whoever says, ‘You fool,’ shall be guilty enough to go into the fiery hell.

Also, in Leviticus 19:18 (NASB)

You shall not take vengeance, nor hold any grudge against the sons of your people, but you shall love your neighbor as yourself; I am the Lord.

Then in Matthew 5:43-45 (NASB)

43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ 44 But I say to you, love your enemies and pray for those who persecute you, 45 so that you may prove yourselves to be sons of your Father who is in heaven; for He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.

Answer 1

The short answer to the question is "yes" - the entire sermon on the mount is based around two ideas:

1. The various laws in the Torah most often (but not only) the 10 commandments and other laws
2. The narrow interpretations of many of these laws common at the time.

Jesus Himself emphasised this very point in Matt 5:17-19 by saying (near the beginning of the sermon):

Do not think that I have come to abolish the Law or the Prophets. I have not come to abolish them, but to fulfill them. For I tell you truly, until heaven and earth pass away, not a single jot, not a stroke of a pen, will disappear from the Law until everything is accomplished. So then, whoever breaks one of the least of these commandments and teaches others to do likewise will be called least in the kingdom of heaven; but whoever practices and teaches them will be called great in the kingdom of heaven.

Jesus then selects a series of laws and shows how they should be observed in a broader, more encompassing way and also contextualises them for His time. Take a look at the numerous foot references to Torah laws in (say) BSB for the extent to which this is done.