'Mother's' in the Bible

And he said, They were my brothers, my mother's sons: by the life of the Lord, if you had kept them safe, I would not put you to death.

Now Abimelech, the son of Jerubbaal, went to Shechem to his mother's family, and said to them and to all the family of his mother's father,

So his mother's family said all this about him in the ears of all the townsmen of Shechem: and their hearts were turned to Abimelech, for they said, He is our brother.