en_tn_condensed/act/18/06.md

shook out his garment

This is a symbolic action to indicate that Paul will no longer try to teach the Jews there about Jesus. He is leaving them to God's judgment. (See: rc://en/ta/man/translate/translate-symaction)

May your blood be upon your own heads

Here "blood" stands for the guilt of their actions. Here "heads" refers to the whole person. Paul tells the Jews they are solely responsible for the judgment they will face for their stubbornness if they refuse to repent. AT: "You alone bear the responsibility for your punishment for sin" (See: rc://en/ta/man/translate/figs-metonymy and rc://en/ta/man/translate/figs-synecdoche)