Charles Ellicott Commentary 2 Samuel 16:7

"And thus said Shimei when he cursed, Begone, begone, thou man of blood, and base fellow:" — 2 Samuel 16:7 (ASV)

Come out, come out. —Rather, Go out, go out. It is doubtful whether by the words thou bloody man, Shimei meant anything more than that he considered David responsible for the blood of the house of Saul (2 Samuel 16:8), especially in the case of Ishbosheth and of Abner, and the execution of Saul’s seven descendants at the demand of the Gibeonites (2 Samuel 21:1–9). Yet he may have known of the crime in regard to Uriah, and have wished to point his curse with the charge of shedding that innocent blood.