2 Kings 10:15-16
10:15 When he left there, he met Jehonadab, son of Rekab, who had been looking for him. Jehu greeted him and asked, “Are you as committed to me as I am to you?” Jehonadab answered, “I am!” Jehu replied, “If so, give me your hand.” So he offered his hand and Jehu pulled him up into the chariot.
10:16 Jehu said, “Come with me and see how zealous I am for the Lord’s cause.” So he took him along in his chariot.