Ambrose of Milan

Boast not thyself then that thou hast been a good servant. Thou hast done what thou oughtest to have done. The sun obeys, the moon submits herself, the angels are subject; let us not then seek praise from ourselves. Therefore He adds in conclusion, So likewise ye, when ye have done all good things, say, We are unprofitable servants, we have done that which it was our duty to do.