Jewish context of Jesus' teachings: An allusion with layers of meaning

In the church year, this Sunday's focus is forgiveness: we read about Joseph forgiving his brothers, and we read Jesus' teaching on forgiveness. Peter asked him how many times he must forgive his brother: Should he forgive him seven times? As you may know: 

Jesus said to him, I say to you not seven times: but, seventy sevens. (Matthew 18:22)

There were symbolic numbers in play. I'm not convinced that Peter meant literally 7 when he asked; the number 7 is associated already in classical Jewish culture with completeness, with Sabbath, with forgiveness and rest. So Peter's question may not have been strictly about accounting. I have never heard a preacher suggest that Jesus' answer was about accounting. There is an agreement that it is a symbolic number indicating a bottomless well of forgiveness, as solidly supported by the parable which Jesus tells next. 

Today, I would like to pause and focus on the number itself. "Symbolic" is not the same as "meaningless", and to get the full weight of meaning, it is worthwhile to stop and unpack the symbolism. "Seventy sevens" is not without precedent. We find the number used prominently in another passage: 

Seventy sevens (weeks) are determined upon your people and upon your holy city, to finish the transgression, and to make an end of sins, and to make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal up the vision and prophecy, and to anoint the most Holy. (Daniel 9:24) 

That prophecy is part of a series of prophecies touching on the restoration of the Temple and the timeline when the Messiah was expected. In those "seventy sevens" we would expect transgressions to end, reconciliation to be accomplished, righteousness to be restored, and the Most Holy to be anointed. The age of God's favor toward humanity is inaugurated. It is a discussion for another day about all the nuances of Daniel's prophecy; it enough for today that Jesus' words likely would have struck his hearers as an echo of Daniel's prophecy of forgiveness, restoration, and the coming of the Holy One. 

So yes, Jesus' "seventy sevens" were symbolic. Forgiveness is placed in a context of holiness, restoration, and the world to come. When we hear the echoes of Daniel's prophecy, we hear the call to forgive until the era of the Messiah, the age "to finish transgression, to make an end to sin, to make reconciliation for iniquity, to bring in everlasting righteousness, to seal up vision and prophecy, and to anoint the most Holy."