Be a herald of God's goodness, for God rules over you, unworthy though you are. Although your debt to Him is so very great, He is not seen exacting payment from you; and from the small works you do, He bestows great rewards upon you. Do not call God just, for His justice is not manifest in the things concerning you. And if David calls Him just and upright, His Son revealed to us that He is good and kind. He is good, He says, to the evil and to the impious (Luke 6:32).
St. Isaac the Syrian (+700), Ascetical Homilies, Homily 51 (often used against PSA by those who despise the saints and pit them against each other. But they are wrong, for does the saint say David is wrong? The homily is talking about personally calling down God's justice. The saint's point here though is that a just God revealed His kindness in His Son, and thus doesn't have to exact debt from you or unleash justice. One translation even says not to call God just "anymore")
Seventh Century