'Join' in the Bible

King Baasha of Israel invaded Judah and interdicted Ramah by building fortifications around it so no one could enter or leave to join King Asa of Judah.

Then he asked Jehoshaphat, "Will you join me in battle against Ramoth-gilead?"

"I'm with you," Jehoshaphat answered the king of Israel. "My army will join yours, and my cavalry will be your cavalry." But Jehoshaphat also asked the king of Israel, "Please ask for a message from the LORD, first."