Titus 1:15

Clement of Alexandria Stromata Book III "Omnia" ergo dicit esse "munda mundis; pollutis autem et infidelibus nihil est mundum, sed polluta est eorum et mens, et conscientia."[231]

Five Books in Reply to Marcion

Reprobate in your very mind,[60]

Cyprian Epistle LVIII

we do not think that this ought to be alleged as any impediment to heavenly grace. For it is written, "To the pure all things are pure."[7]

Novation On the Jewish Meats

For the illustrious Master, and the heavenly Teacher, and the ordainer of the perfected truth, has come, under whom at length it is rightly said: "To the pure all things are pure but unto them that are defiled and unbelieving is nothing pure, but even their mind and conscience is defiled."[21]

Origen Commentary on Matthew Book XI

But as for the things which are called impure, "All things become pure to the pure," for, "To them that are defiled and unbelieving nothing is pure, since both their minds and their conscience are defiled."[101]