Exodus - Chapter 21
We now have a few chapters setting out some rules in more detail, to assist the judges. In verse 21 we see that the payment to be made in compensation for a slave being gored (pierced) is 30 pieces of silver.
In Matthew 26 Judas agrees to hand Jesus over to the Jewish leaders, who will then have him put on a cross and pierced. The payment he receives is 30 pieces of silver.
And on the evening when Judas betrays him, Jesus washes Judas' feet - the act of a servant or slave.