It is striking that she does so. She does not mean that Shamgar and Jael were themselves responsible for the sad condition during the time of oppression before she arose. Rather, she wanted to highlight the lack of leadership at this time. The Lord had to use two foreigners to rescue his people, including one whose name celebrates a pagan goddess.
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6 “In the days of Shamgar, son of Anath, in the days of Jael, the highways were abandoned, and travelers kept to the byways.