Don’t avenge yourself against anybody

Leviticus 19:18 says, “Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbor as thyself: I am the LORD.”  Theoretically, if we are all descendents of Noah (everyone else died in the flood) should the Israelites hurt anyone?  You know, like they have earlier in this book?  Doesn’t this contradict Exodus 21:23 “And if any mischief follow, then thou shalt give life for life, 21:24 "Eye for eye, tooth for tooth, hand for hand, foot for foot,

21:25 Burning for burning, wound for wound, stripe for stripe.”  That sounds like vengeance to me.