2 Samuel 20:9-10

9Joab said to Amasa, “Is it going well with you, my brother?” And with his right hand Joab took hold of Amasa by the beard [as if] to kiss him [in greeting].

10But Amasa [who had replaced Joab as David’s commander] was off guard and not attentive to the sword in Joab’s hand. So Joab struck Amasa in the abdomen with the sword, spilling his intestines to the ground. Without another blow Amasa died. Then Joab and Abishai his brother pursued Sheba the son of Bichri.