11:6 And if by grace, then it is no more of works - Whether ceremonial or moral. Else grace is no longer grace - The very nature of grace is lost. And if it be of works, then it is no more grace: else work is no longer work - But the very nature of it is destroyed. There is something so absolutely inconsistent between the being justified by grace, and the being justified by works, that, if you suppose either, you of necessity exclude the other. For what is given to works is the payment of a debt; whereas grace implies an unmerited favour. So that the same benefit cannot, in the very nature of things, be derived from both.

Romans 11:6 Parallel Commentaries

Now this Election the Apostle Demonstrating to Be...
17. Now this election the Apostle demonstrating to be, not of merits going before in good works, but election of grace, saith thus: "And in this time a remnant by election of grace is saved. But if by grace, then is it no more of works, otherwise grace is no more grace." [2672] This is election of grace; that is, election in which through the grace of God men are elected: this, I say, is election of grace which goes before all good merits of men. For if it be to any good merits that it is given, …
St. Augustine—On Patience

History of Arian Opinions.
Arius's own sentiments; his Thalia and Letter to S. Alexander; corrections by Eusebius and others; extracts from the works of Asterius; letter of the Council of Jerusalem; first Creed of Arians at the Dedication of Antioch; second, Lucian's on the same occasion; third, by Theophronius; fourth, sent to Constans in Gaul; fifth, the Macrostich sent into Italy; sixth, at Sirmium; seventh, at the same place; and eighth also, as given above in §8; ninth, at Seleucia; tenth, at Constantinople; eleventh, …
Athanasius—Select Works and Letters or Athanasius

Epistle Xliii. To Eulogius and Anastasius, Bishops.
To Eulogius and Anastasius, Bishops. Gregory to Eulogius, Bishop of Alexandria, and Anastasius, Bishop of Antioch. When the excellent preacher says, As long as I am the apostle of the Gentiles I will honour my ministry (Rom. xi. 13); saying again in another place, We became as babes among you (1 Thess. ii. 7), he undoubtedly shews an example to us who come after him, that we should retain humility in our minds, and yet keep in honour the dignity of our order, so that neither should our humility be …
Saint Gregory the Great—the Epistles of Saint Gregory the Great