Judges 8:30,31

‘ And Gideon had seventy sons begotten from his own body (literally ‘going out of his thigh'), for he had many wives. And his concubine who was in Shechem she also bore him a son, and he called his name Abimelech.'

Having been made sole ruler of his territory he began to behave like it. He married many wives and had many children. ‘Seventy' indicates divine perfection intensified. Polygamy was not frowned on in those days but was mainly the privilege of the rich. But excessive polygamy always led to trouble, especially in the matter of inheritance of a kingship. It was specifically forbidden to those who would rule Israel (Deuteronomy 17:17).

A concubine is a slave wife or a wife of lower class coming without dowry, not suited to full wife status (Judges 9:18), whose son would not be in line to inherit. Her son would grow up antagonistic to the ‘true' sons. It appears she continued to live at Shechem, presumably with her father, probably so that she was available when Gideon spent time there judging the people. While she may not have been a worshipper of Baal she would undoubtedly have been heavily influenced in that direction and her religion was probably syncretistic, with ‘lord of the covenant' (Baal-berith) being worshipped along with Yahweh, the true Lord of the Covenant, even possibly as Yahweh, but with ‘strange' rites.

Abimelech's name means ‘the king is my father', probably given so that he had some prestige among his fellows especially in Shechem and to please his concubine. It proved to be a mistake for it gave him great ideas of his own importance. We should beware of giving ideas to people unless we intend them to be carried out. But originally such a name meant ‘Melech is my father' (or Molech - with the vowels changed to those of ‘bosheth' meaning shame) - possibly significant to the writer in the light of the fact that he slew his brothers as sacrifices in his father's name - it was Melech who demanded human sacrifice. Thus his mother may have worshipped Melech.