Choose your words carefully.
He that keeps his mouth keeps his life;
He that opens his lips too wide shall bring on his own destruction [Proverbs 13:3].
Bite your tongue until it bleeds.
The pain is worth more than what you have to say.
Swallow your pride.
Swallow your pride because silence is golden, and I wouldn't pay a penny to hear your thoughts.
Lie down your guard.
Lie down your guard and surrender.