2 Whereas, therefore, in every question, which relates to life and conduct, not only teaching, but exhortation also is necessary; in order that by teaching we may know what is to be done, and by exhortation may be incited not to think it irksome to do what we already know is to be done; what more can I teach you, than what we read in the Apostle? For holy Scripture sets a rule to our teaching, that we dare not “be wise more than it behooves to be wise;” but be wise, as himself says, “unto soberness, according as unto each God has allotted the measure of faith.” Be it not therefore for me to teach you any other thing, save to expound to you the words of the Teacher, and to treat of them as the Lord shall have given to me.
Source: On the Good of Widowhood (New Advent)