2 Samuel 20:4-8

Now the king said to Amasa, “Summon the men of Judah for me within three days, and be present here yourself.”

So Amasa went to summon the men of Judah, but he was delayed longer than the set time which he had designated for him.

And David said to Abishai, “Now Sheba the son of Bichri will do us more harm than Absalom; take your lord’s servants and pursue him, so that he does not find for himself fortified cities and escape from our sight.”

So Joab’s men went out after him, along with the Cherethites, the Pelethites, and all the warriors; and they left Jerusalem to pursue Sheba the son of Bichri.

When they were at the large stone which is in Gibeon, Amasa came to meet them. Now Joab was dressed in his military attire, and over it he had a belt with a sword in its sheath strapped on at his waist; and as he went forward, it fell out.