Sirach 6:15

15 Nothing doth countervail a faithful friend, and his excellency is invaluable.

Sirach 6:15 In-Context

13 Separate thyself from thine enemies, and take heed of thy friends.
14 A faithful friend is a strong defence: and he that hath found such an one hath found a treasure.
15 Nothing doth countervail a faithful friend, and his excellency is invaluable.
16 A faithful friend is the medicine of life; and they that fear the Lord shall find him.
17 Whoso feareth the Lord shall direct his friendship aright: for as he is, so shall his neighbour be also.

The Brenton translation of the Septuagint is in the public domain.