Albert Barnes Commentary Luke 17:3-4

"Take heed to yourselves: if thy brother sin, rebuke him; and if he repent, forgive him. And if he sin against thee seven times in the day, and seven times turn again to thee, saying, I repent; thou shalt forgive him." — Luke 17:3-4 (ASV)

Trespass against you. Sin against you, or does anything that gives you an offence or does you an injury.

Rebuke. Reprove. Go and tell him his fault, and seek an explanation. Acquaint him with what has been the effect of his conduct, and the state of your feelings, that he may acknowledge his error and repent.