Sirach 12:8-10

New Revised Standard Version Catholic Edition

⁸ A friend is not known^[a] in prosperity,
    nor is an enemy hidden in adversity.
⁹ One’s enemies are friendly^[b] when one prospers,
    but in adversity even one’s friend disappears.
¹⁰ Never trust your enemy,
    for like corrosion in copper, so is his wickedness.