en_tn/luk/17/03.md

If your brother sins

This is a conditional statement that talks about an event that will probably happen in the future.

your brother

This normally includes "your fellow-believer" as well as actual "brothers" who were born to the same mother and father.

rebuke him

"warn him strongly" or "tell him strongly that what he did was wrong" or "correct him"

If he sins against you seven times

This is a hypothetical future situation. It may never happen, but even if it does, Jesus tells people to forgive.

seven times in the day

This could be translated as "many times in a day." The number seven in the Bible is a symbol for completeness.