John Chrysostom (attributed)

Otherwise; the precepts of Moses are easy to obey; Thou shall not kill. Thou shall not commit adultery. The very greatness of the crime is a check upon the desire of committing it; therefore the reward of observance is small, the sin of transgression great. But Christ’s precepts, Thou shalt not be angry, Thou shalt not lust, are hard to obey, and therefore in their reward they are great, in their transgression, ‘least.’ It is thus He speaks of these precepts of Christ, such as Thou shall not be angry, Thou shalt not lust, as ‘the least;’ and they who commit these lesser sins, are the least in the kingdom of God; that is, he who has been angry and not sinned grievously is secure from the punishment of eternal damnation; yet he does not attain that glory which they attain who fulfil even these least.