He spoke to himself, and conversed with himself, as these words show: “I said, I will take heed to my ways” (Psalm 38:1).
Solomon his son also said: “Drink water out of thine own vessels, and out of the springs of thy wells” (Prov. 5:15); that is: use thine own counsel.
For: “Counsel in the heart of a man is as deep waters” (Prov. 20:5).
“Let no stranger,” it says, “share it with thee. Let the fountain of thy water be thine own, and rejoice with thy wife who is thine from thy youth. Let the loving hind and pleasant doe converse with thee” (Prov. 5:17-19).
[…] Moses…when silent, was crying out (Ex. 14:16); who, when he stood at ease, was fighting, nay, not merely fighting but triumphing over enemies whom he had not come near.
[…] Moses in his silence spoke, and in his ease laboured hard. And were his labours greater than his times of quiet, who, being in the mount for forty days, received the whole law? (Ex. 24:17). And in that solitude there was One not far away to speak with him.
Whence also David says: “I will hear what the Lord God will say within me” (Ps. 84:18). How much greater a thing is it for God to speak with any one, than for a man to speak with himself!
[…] When can the upright man be alone, since he is always with God? When is he left forsaken who is never separated from Christ?
“Who,” it says, “shall separate us from the love of Christ? I am confident that neither death nor life nor angel shall do so” (Rom. 8:35, 38).
And when can he be deprived of his labour who never can be deprived of his merits, wherein his labour receives its crown? By what places is he limited to whom the whole world of riches is a possession?
By what judgment is he confined who is never blamed by anyone? For he is “as unknown yet well known, as dying and behold he lives, as sorrowful yet always rejoicing, as poor yet making many rich, as having nothing and yet possessing all things” (2 Cor. 6:9ff).
For the upright man regards nothing but what is consistent and virtuous. And so although he seems poor to another, he is rich to himself, for his worth is taken not at the value of the things which are temporal, but of the things which are eternal.
Ambrose of Milan (c. 337-397): On the Duties of the Clergy, book 3, chapter 1, 1-2,7.