7 I have sent you also other books which you did not ask, that I might not rigidly restrict myself to what you asked:— my works on Faith in Things Unseen, on Patience, on Continence, on Providence, and a large work on Faith, Hope, and Charity. If, while you are in Africa, you shall read all these, either send your opinion of them to me, or let it be sent to some place whence it may be sent us by my lord and brother Aurelius, though wherever you shall be we hope to have letters from you; and do you expect letters from us as long as we are able. I most gratefully received the things you sent to me, in which you deigned to aid me both in regard to my bodily health, since you desire me to be free from the hindrance of sickness in devoting my time to God, and in regard to my library, that I may have the means to procure new books and repair the old. May God recompense you, both in the present life and in that to come, with those favours which He has prepared for such as He has willed you to be. I request you now to salute again for me, as before, the pledge of peace entrusted to you, very dear to both of us.
Source: Letters (New Advent)