15 And when he departed from there, he met Jehonadab the son of Rechab coming to meet him. And he greeted him and said to him, "Is your heart true to my heart as mine is to yours?" And Jehonadab answered, "It is." Jehu said,[1]"If it is, give me your hand." So he gave him his hand. And Jehu took him up with him into the chariot. 16 And he said, "Come with me, and see my zeal for the Lord." So he[2] had him ride in his chariot. 17 And when he came to Samaria, he struck down all who remained to Ahab in Samaria, till he had wiped them out, according to the word of the Lord that he spoke to Elijah.
18 Then Jehu assembled all the people and said to them, "Ahab served Baal a little, but Jehu will serve him much. 19 Now therefore call to me all the prophets of Baal, all his worshipers and all his priests. Let none be missing, for I have a great sacrifice to offer to Baal. Whoever is missing shall not live." But Jehu did it with cunning in order to destroy the worshipers of Baal. 20 And Jehu ordered, "Sanctify a solemn assembly for Baal." So they proclaimed it. 21 And Jehu sent throughout all Israel, and all the worshipers of Baal came, so that there was not a man left who did not come. And they entered the house of Baal, and the house of Baal was filled from one end to the other. 22 He said to him who was in charge of the wardrobe, "Bring out the vestments for all the worshipers of Baal." So he brought out the vestments for them. 23 Then Jehu went into the house of Baal with Jehonadab the son of Rechab, and he said to the worshipers of Baal, "Search, and see that there is no servant of the Lord here among you, but only the worshipers of Baal."
Matthew Henry's Commentary on 2 Kings 10:15-23
Commentary on 2 Kings 10:15-28
(Read 2 Kings 10:15-28)
Is thine heart right? This is a question we should often put to ourselves. I make a fair profession, have gained a reputation among men, but, is my heart right? Am I sincere with God? Jehonadab owned Jehu in the work, both of revenge and of reformation. An upright heart approves itself to God, and seeks no more than his acceptance; but if we aim at the applause of men, we are upon a false foundation. Whether Jehu looked any further we cannot judge. The law of God was express, that idolaters were to be put to death. Thus idolatry was abolished for the present out of Israel. May we desire that it be rooted out of our hearts.