Deuterocanon

Sirach 22:25

Ben Sira, Ecclesiasticus

25 I am not ashamed to shelter a friend, and I will not hide from him. 26 But if harm should come to me because of him, whoever hears of it will beware of him. 27 Who will set a guard over my mouth, and an effective seal upon my lips, so that I may not fall because of them, and my tongue may not destroy me?

Date: 195-175 B.C.E.
* Dates are based on scholarly estimates

Ambrose On the Duty of the Clergy 3.22

128 Open your breast to a friend that he may be faithful to you, and that you may receive from him the delight of your life. For a faithful friend is the medicine of life and the grace of immortality. Give way to a friend as to an equal, and be not ashamed to be beforehand with your friend in doing kindly duties. For friendship knows nothing of pride. So the wise man says: Do not blush to greet a friend. Do not desert a friend in time of need, nor forsake him nor fail him, for friendship is the support of life. Let us then bear our burdens as the Apostle has taught: for he spoke to those whom the charity of the same one body had embraced together. If friends in prosperity help friends, why do they not also in times of adversity offer their support? Let us aid by giving counsel, let us offer our best endeavours, let us sympathize with them with all our heart.

Date: 390-395 C.E.
* Dates are based on scholarly estimates