The wretch who doth not give to others their due, who is of wicked soul, who is ungrateful, and shameless, should, O king, be avoided. The guilty person who provoketh another about him that is innocent, cannot sleep peacefully at night, like a person passing the night with a snake in the same room. They, O Bharata, who upon being angry endanger one’s possessions and means of acquisition, should always be propitiated like the very gods.

In plain words: Stay away from people who don't give others what they deserve, who are wicked, ungrateful and shameless. A person who makes trouble for an innocent person can't sleep peacefully, like someone sharing a room with a snake. People whose anger could cost you your livelihood should be kept happy with great care.