Mercy And Salvation

Et in misericordia tua disperdes inimicos meos. Et perdes omnes inimicos qui persequuntur animam meam: quoniam servus tuus sum ego. Habuit quidem, ut diximus, hoc justitia verecundiae, ut quidquid illud sibi beatitudinis sperat, id pro magnificentia Dei potius, quia Deo beata et aeterna et bona tribuere sit dignum, quam pro merito suo postulet. Sed tamen praeferens honorem et misericordiam Dei: merendi quoque id per se non exclusit officium. Nam cum vivificandus sit, vivificandus tamen est in aequitate; quia aequum sit vitam retribui stipendiis sanctitatis. Et cum per misericordiam Dei educto eo de tribulatione disperdendi sint ejus inimici, jam non est misericordia indiscreti confusique judicii; cum quae a tribulatione educit, eadem disperdat inimicos: quia ex meritorum diversitate, vel in poenam, vel in misericordiam judicium temperatur. Non leves autem sibi esse inimicos Propheta demonstrat, sed eos qui etiam animam persequantur: non quod cum corpore possit occidi, sed quod ita diabolicis infestationibus fatigetur, et sub injectorum sibi vitiorum incendiis aduratur, ut a Domino mereatur occidi. Verum ut etiam inimici sui pereant, quamquam ad id potissimum et nomen et misericordia Dei est; tamen cum etiam ea causa est, quod servus Dei est, cujus animam persequantur: et liberalitas ex parte Dei admiscetur, et meritum ex parte hominis; atque ad Domini misericordiam, servi quoque et fides et nomen adjungitur: ut misericordia Dei quamquam omnibus prompta sit, his tamen qui servi ejus sunt intelligatur assistere, per eum et in eo qui ait: Ego sum vobiscum omnibus diebus usque ad consummationem saeculi. Sanctus Hilarius Pictaviensis, Tractatus super Psalmos, Tractatus in Psalmum CXLII Source: Migne PL 9.842c-843a

And in your mercy you scatter my enemies. You destroy all the enemies who persecute my soul, because I am your servant. 1 He has, as we have said, the righteousness of the humble, so that whatever blessing he hopes for himself, because it befits God to give blessed and eternal goods, he asks for it from the magnificence of God rather than on account of his own merit. But even though he gives precedence to the honour and mercy of God, he does not exclude the office of merit for himself. For when a man is worthy of being given life, he is revived on account of righteousness, since the rewards of sanctity are given to a righteous life. And when by the scattering of enemies the mercy of God leads him from tribulation, it is not the mercy of some sort of vague and obscure judgement that leads from tribulation with the scattering of enemies, but the judgement is fashioned by a mixture of merit, fault, and mercy. Then the Prophet shows that his enemies are not light things, but those who persecute the soul. Not that which can kill the body, but that which will wear down with devilish infestations, and burn with the fires of injected vices, which merits death from the Lord. 2 Truly so that his enemies shall perish, although this is a matter for the most powerful name and mercy of God, yet with it is the cause that he whose soul is persecuted is a servant of God, and thus the largess on the part of God shall be mixed with merit on the part of man, and thus the faith and name of the servant is joined to the mercy of God, so that the mercy of God is understood to be ready to help all who may be understood to be His servant, through Him and in Him who said: 'I am with you every day until the end of the ages.' 3 Saint Hilary of Poitiers, Homilies on the Psalms, from Psalm 142 1 Ps 142.12 2 Mt 10.28 3 Mt 28.20