Matthew 18:21-35 Forgive Because You Have Been Forgiven.
As Luke pointed out in more of a summary of Matthew’s previous passage, if a brother sins against oneself they are to be rebuked, and if they repent they are to be forgiven (17:3). Luke then records Jesus reiterating that this has no limit, the number seven in the bible being symbolic of perfection (v. 4). Matthew recorded that Peter had asked the question (v. 21), and Luke records Jesus answer in the affirmative. However, Matthew records further what follows, that he was not fixing a limit, but just the opposite (v. 22). Seven being symbolic of perfection meant that there was to be no limit – if one repents then they are to be forgiven, with no limit. However, repentance from a biblical perspective often means more than simply saying one is sorry. Sometimes what is involved is the settling of accounts.
The sincerity one’s forgiveness may also involve being patient with the offender if restitution is involved. Ultimately God is the King who will settle accounts with everyone, and how one has conducted themselves in this area will be exposed (vv. 23-27). Furthermore, those who are forgiven by God are also expected to forgive others (vv. 28-35 Cf. 6:12-15; Mk. 11:25-26; Col. 3:13). The law may also be in view here, where a fellow covenant member may have to serve as a worker, who must then be released in the seventh year of rest (Ex. 21:2), or the year of Jubilee (Lev. 25:39-41). This is the obligation that Elisha helped the widow to fulfill (II Kgs. 4:1-7). Nehemiah also had to deal with a similar situation (5:1ff.). No other human could sin against us more than we have sinned against God (Lk. 7:41-43). Mercy must triumph over judgment (Js. 2:13).