2 Samuel 3:9; 2 Samuel 3:35

9 May God deal with Abner, be it ever so severely, if I do not do for David what the LORD promised him on oath

35 Then they all came and urged David to eat something while it was still day; but David took an oath, saying, “May God deal with me, be it ever so severely, if I taste bread or anything else before the sun sets!”