So why did Jesus ask his followers to turn the other cheek rather than seek some retaliatory eye for eye retribution? Because he was against retaliation, was he not?.........
Outside of Biblical law was: retaliation.
Biblical law as found in the Bible was equal justice - Leviticus 19:18 ( Golden Rule )
Please notice at Matthew 5:38 is the word ' heard ' ( Not 'written' but 'heard' )
This is because Jesus was saying that is what the people ' heard ' ( word of mouth Not Scripture )
When Jesus referred to the Law he prefaced his statements with the words, " It is written...."
Meaning already written down in the OT, and Not ' hearsay ' as the people ' heard '.
Revenge was what the pagan nations taught and that is what the people 'heard' with their ears, Not what was written down.
The Mosaic Law served against intentional harm - Deuteronomy 19:20; 32:35 - disciplined to the proper degree.
( Exodus 21:28-30; Numbers 35:22-25