Sirach 29:17

17 And he that is of an unthankful mind will leave him that delivered him.

Sirach 29:17 In-Context

15 Forget not the friendship of thy surety, for he hath given his life for thee.
16 A sinner will overthrow the good estate of his surety:
17 And he that is of an unthankful mind will leave him that delivered him.
18 Suretiship hath undone many of good estate, and shaken them as a wave of the sea: mighty men hath it driven from their houses, so that they wandered among strange nations.
19 A wicked man transgressing the commandments of the Lord shall fall into suretiship: and he that undertaketh and followeth other men's business for gain shall fall into suits.

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