Sirach 12:8-10

Revised Standard Version

⁸ A friend will not be known^[a] in prosperity,
    nor will an enemy be hidden in adversity.
⁹ A man’s enemies are grieved when he prospers,
    and in his adversity even his friend will separate from him.
¹⁰ Never trust your enemy,
    for like the rusting of copper, so is his wickedness.