Patristic A.D. 397
“(in Luc. vi. 22.) The merciful loses the benefit of his mercy, unless he shews it from a pure heart; for if he seeks to have whereof to boast, he loses the fruit of his deeds; the next that follows therefore is, Blessed are the pure in heart.”
Catena Aurea: Gospel of Matthew, as excerpted in the Catena Aurea on Matthew 5:8
PD · J. H. Newman (Oxford, 1841) ↗