Given its prominence in the NT, it’s striking that the LXX rarely speaks of “breaking bread.”  One of the few times the phrase occurs is in Jeremiah 16:7, where, strikingly, it is joined to a statement about a “cup of consolation.”  Broken bread and cup is Eucharistic.

Jeremiah is warning about the calamity about to fall on Jerusalem: Marriages will end, people will die and be exposed without burla, there will be no voice of bride or groom.  Likewise, there will be a cessation of funeral meals: No more “breaking bread in mourning” and no more “cupt of consolation to drink for anyone’s father or mother.”

Jesus’ broken bread and cup of consolation are a funeral meal - more precisely, a pre-funeral meal mourning His approaching death.  And like Jeremiah Jesus speaks of an interruption of the meal - no more “fruit of the vine until I drink it new with you in My Father’s kingdom” (Matthew 26:29).  Jesus is prophesying a kind of exile, time of distress, Messianic woes, but a distress that will later be reversed in a resurrection/return from exile.