With accent marks:
Не руби́ сук, на кото́ром сиди́шь.
Do not chop the branch you sit on
This proverb is addressed to a person who harms himself by his actions.
The English equivalent of this proverb is "To shoot oneself in the foot".
Other Russian proverbs
Put your trust in God, but don't make mistakes yourself
Better late than never.
Poor people are inventive.
You can't spoil the porridge with butter.
You can't help grief with tears.
A wolf is fed by his legs
You see your friends in the times of trouble.
All is well that ends well.