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.
Cross-reference
Ezra 10:19 has men giving their hand as a pledge to put away foreign wives, the same gesture Jehu uses to seal agreement.
Jeremiah 35:6 records the Rechabites' obedience to their ancestor Jehonadab (the same man Jehu met).
Jeremiah 35:8 continues the Rechabites' commitment to follow Jehonadab's commands, echoing their founder's faithfulness.
Jeremiah 35:14-19 praises the Rechabites for obeying Jehonadab's commands, linking back to the ancestor Jehu allied with.
Galatians 2:9 describes giving the right hand of fellowship, directly paralleling Jehu's giving of the hand as a sign of alliance.
Jeremiah 35:2 introduces the Rechabites, descendants of Jehonadab. This connects Jehu's ally to a later faithful clan.
1 Chronicles 2:55 lists the Rechabites among the Kenite clans, connecting to Jehonadab's lineage mentioned in 2 Kings.
Ezekiel 17:18 condemns breaking a covenant after giving the hand, using the same hand-pledge imagery as Jehu's request.