Targum Jonathan transforms the dry legal code of (Deuteronomy 19) into something visceral. Where the Torah simply warns that the blood avenger might overtake a fleeing killer, the Targum says the avenger pursues with "his heart boiling within him on account of his grief." That phrase—the boiling heart—appears nowhere in the Hebrew. It is the Targum's own psychological portrait of a man consumed by rage and sorrow.
The accidental manslayer's example gets vivid physical detail. The iron flies "apart from the haft" and lights on a neighbor. The Targum wants you to see the axe head spinning through the air. It specifies the killer "had not kept enmity against him yesterday, or the day before," turning the Torah's legal language into something closer to courtroom testimony.
On the expansion of cities of refuge, the Targum adds a conditional promise. If God enlarges the border "as He hath sworn to your fathers," then Israel must add three more cities to the original three—for a total of six. The purpose is stated with brutal clarity: "that innocent blood may not be shed in your land."
The witness laws receive the Targum's most significant theological addition. Where the Torah requires two or three witnesses, Targum Jonathan inserts a remarkable clause: "by the Word of the Lord, to insure retribution upon secret crimes." Even when human witnesses fail, God's Memra—His divine Word—ensures justice for hidden sins. The Targum also specifies that false witnesses face exactly the punishment "they had devised to do against their brother." And the lex talionis gets softened—"the value of an eye for an eye, the value of a tooth for a tooth"—making explicit the rabbinic interpretation that monetary compensation, not physical mutilation, is what the law demands.