A.T. Robertson Commentary James 2:13

"For judgment [is] without mercy to him that hath showed no mercy: mercy glorieth against judgment." — James 2:13 (ASV)

Without mercy (ανελεος). Found here only save a doubtful papyrus example (ανελεως) for the vernacular ανιλεως and the Attic ανηλεης. For this principle of requital see Mt 5:7; 6:14; 7:1f.; 18:33.

Glorieth against (κατακαυχατα). Present middle indicative of the old compound verb κατακαυχαομα, to exult over (down), in N.T. only here, 3:14; Romans 11:18. Only mercy can triumph over justice with God and men. "Mercy is clothed with the divine glory and stands by the throne of God" (Chrysostom). See Ro 8:31-39; Matthew 9:13; 12:7.