Matthew 5:23

23 “Therefore, if you are offering your gift at the altar and there remember that your brother or sister has something against you,

Read Matthew 5:23 Using Other Translations

Therefore if thou bring thy gift to the altar, and there rememberest that thy brother hath ought against thee;
So if you are offering your gift at the altar and there remember that your brother has something against you,
“So if you are presenting a sacrifice at the altar in the Temple and you suddenly remember that someone has something against you,