Sirach 12:10-12

New Revised Standard Version, Anglicised Catholic Edition

¹⁰ Never trust your enemy,
    for like corrosion in copper, so is his wickedness.
¹¹ Even if he humbles himself and walks bowed down,
    take care to be on your guard against him.
Be to him like one who polishes a mirror,
    to be sure it does not become completely tarnished.
¹² Do not put him next to you,
    or he may overthrow you and take your place.
Do not let him sit at your right hand,
    or else he may try to take your own seat,
and at last you will realize the truth of my words,
    and be stung by what I have said.