Judges 9:30-33 NIV

30 When Zebul the governor of the city heard what Gaal son of Ebed said, he was very angry.
31 Under cover he sent messengers to Abimelek, saying, “Gaal son of Ebed and his clan have come to Shechem and are stirring up the city against you.
32 Now then, during the night you and your men should come and lie in wait in the fields.

References for Judges 9:32

33 In the morning at sunrise, advance against the city. When Gaal and his men come out against you, seize the opportunity to attack them.”

References for Judges 9:33