Midrasch zu Schemuel II 10:16

And it came to pass in the days of Amraphel (Gen. 14:1). R. Tanhuma the son of Abba opened the discussion with the verse The wicked began with the sword, and have bent their bow; to cast down the poor and the needy, to slay such as are upright in the way; their sword shall enter into their own heart, and their bows shall be broken (Ps. 37:14–15). The wicked began with the sword alludes to Cain, who slew his brother Abel before any other man was slain. Their sword shall enter into their own heart refers to the fact that Lamech later killed Cain. Another comment on The wicked began with the sword: This refers to Hanun the son of Nahash. Why? After the death of his father, David sent messages by the hand of his servants to comfort him (II Sam. 10:2), but Hanun seized David’s servants, shaved off half their beards and cut off their garments in the middle, even to their buttocks, and sent them away (ibid., v. 4). Hanun then dispatched emissaries to Aram-naharaim to hire thirty-two thousand charioteers in addition to the tens of thousands of troops he had in his army.¹¹II Sam. 10:16. They all assembled and encamped in one place. The Holy One, blessed be He, said to him: Wicked one, you began with the sword, hence the sword will penetrate your heart. Therefore, Joab and Abishai destroyed them all, as it is said: So Joab and the people that were with him drew nigh unto the battle to meet the Arameans; and they fled before them (ibid., v. 13).

"The children of Ammon came against Israel relying upon the strength of Shovach." It is written (II Sam. 10, 16) Shovach, and again it is written (I Chr. 19, 16) Shofach. R. Ishmael and R. Samuel, and according to others R. Ami and R. Assi explained both passages, one said that his real name was Shovach, and why was he called Shofach? Because whoever saw him, was poured out before him like a ladle, [his courage failed him]. The other one said: "His real name was Shofach, and why was he called Shovach? Because he was built like a dove-cot, [high-statute]." (Jer. 5, 16) Their quiver is as an open sepulchre: they are all mighty men. R. Samuel, and according to others, R. Ami and R. Assi differ as to the meaning of this passage. One said that it means: "When he threw an arrow he slew heaps in the army of Nebuchadnezzar, and if one will think that this was because they were so skilled in warfare and nothing else, it is said: "They are all mighty men." But the other one said that this refers to their own personality and with their own conduct. (Pr. 12, 25) If there be care in the heart of man, let him suppress. R. Ami and R. Assi differ in the explanation of this passage, one said that this means: "He should forget about it," and the other one said: "He should relate it to others."