Sirach 12:15

15 For a while he will abide with thee, but if thou begin to fall, he will not tarry.

Sirach 12:15 In-Context

13 Who will pity a charmer that is bitten with a serpent, or any such as come nigh wild beasts?
14 So one that goeth to a sinner, and is defiled with him in his sins, who will pity?
15 For a while he will abide with thee, but if thou begin to fall, he will not tarry.
16 An enemy speaketh sweetly with his lips, but in his heart he imagineth how to throw thee into a pit: he will weep with his eyes, but if he find opportunity, he will not be satisfied with blood.
17 If adversity come upon thee, thou shalt find him there first; and though he pretend to help thee, yet shall he undermine thee.

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