2 Samuel 20:8-10

20:8 When they were near the big rock that is in Gibeon, Amasa came to them. Now Joab was dressed in military attire and had a dagger in its sheath belted to his waist. When he advanced, it fell out.

20:9 Joab said to Amasa, “How are you, my brother?” With his right hand Joab took hold of Amasa’s beard as if to greet him with a kiss. 20:10 Amasa did not protect himself from the knife in Joab’s other hand, and Joab stabbed him in the abdomen, causing Amasa’s intestines to spill out on the ground. There was no need to stab him again; the first blow was fatal. Then Joab and his brother Abishai pursued Sheba son of Bicri.