In the sermon on the mount, Jesus will often take a “law” and redefine it in such a way that it becomes about the heart and not just the action.
“Don’t hate your enemies. Love your enemies. Pray for them.”
“When you hate your brother, it is as if you have murdered your brother.”
“When you look upon someone lustfully, then you have committed adultery”.
Why would Jesus do that? Why would he take commands which were hard enough to keep in “the flesh” and make them about the heart, the mind, and condition of our soul?
That seems unnecessarily unfair even if it is true. However, what Jesus is setting before us is a new way, a new hope and better covenant.
Hebrews 8:6 6 But the ministry Jesus has received is as superior to theirs as the covenant of which he is mediator is superior to the old one, and it is founded on better promises.