2 Kings 10:15
And when he was departed thence, he lighted on Jehonadab the son of Rechab coming to meet him: and he saluted him, and said to him, Is thine heart right, as my heart is with thy heart? And Jehonadab answered, It is. If it be, give me thine hand. And he gave him his hand; and he took him up to him into the chariot.
Jehonadab gave Jehu his hand and was lifted up by that hand to a place in his chariot, where he came to understand Jehu's zeal for the Lord and the principles that moved him to action. In that meeting Jehu held up his zeal for the Lord as the reason for Jehonadab to join with him.
Jehu stands as a warning against letting self rise in God's work, when zeal pours out in a torrent of words that are harsh and unfitting. Truth aimed at winning souls must therefore be spoken with gentleness and tenderness and with careful love.
It was a sad day for Jehonadab, because the spirit shown by Jehu never truly binds human hearts together. It is unsafe to bind one's interests up with a Jehu religion, since it brings sadness and heaviness of heart upon God's true workers rather than inspiring faith. God may give Jehu a work to do under His own hand and direction, but He has not left His servants to do the work of punishing those who will not heed His warnings and reproofs, and they cannot do that punishing work with success.
By contrast, those led by the Holy Spirit abiding within the heart see their own defects of character, pity the weakness of others, forgive as they wish to be forgiven, and are compassionate, courteous, and Christlike. Jehu's appeal for others to join him pictures people whose zeal draws them away from the workers God is actually leading.