2 Samuel 20:8-10

8When they arrived at the big rock in Gibeon, Amasa came to meet them. Joab was wearing his soldier's clothes. He had a long knife that was tied to his belt. As Joab went towards Amasa, the knife fell to the ground.

9Joab said to Amasa, ‘How are you, my brother?’ He took hold of Amasa's beard with his right hand. He pretended that he wanted to kiss him.

10But Amasa did not see the knife in Joab's other hand. Joab pushed the knife into Amasa's stomach. His inside parts poured out onto the ground. He died immediately. Joab did not have to hit him again. Then Joab and his brother Abishai continued to chase after Sheba.