With accent marks:
Не рой я́му друго́му, сам в неё попадёшь.
Do not dig a hole for another one, you will fall into it yourself.
This proverb is very old and has its analogues in many languages. It is also found in the text of the Bible.
Its meaning is very clear: do not cause trouble to another one, the circumstances can turn against you.
Other Russian proverbs
If I knew where I would fall, I would lay some straw there.
Don't go to the woods if afraid of wolves.
The quieter you go, the further you'll get.
Fear has big eyes.
Silent means consent.
What you will sow, that you will reap.
The further into the forest, the more firewood is there.
Do not look at a given horse's teeth.