2 Samuel 20:7-11

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.

And Joab said to Amasa, “Is it going well for you, my brother?” And Joab took hold of Amasa by the beard with his right hand to kiss him. Amasa Murdered

But Amasa was not on guard against the sword which was in Joab’s hand, so he struck him in the belly with it and spilled out his intestines on the ground, and did not strike him again, and he died. Then Joab and his brother Abishai pursued Sheba the son of Bichri.

Now one of Joab’s young men stood by him and said, “Whoever favors Joab and whoever is for David, follow Joab!”