What does Luke 13:7 mean?
Jesus is telling a final parable about reconciliation (Luke 13:6). The crowd members need to repent of their wrongs to others and to God while they have the chance. If they hesitate, they may face severe judgment, whether the court be earthly or heavenly (Luke 12:57–59; 13:1–5).In the same way, Jesus tells the nation of Israel to wake up and realize their time is short. John the Baptist warned about this with the same metaphor. When Pharisees and Sadducees came to his baptisms, he confronted them with their sin and cautioned them that their status as Jews would not protect them (Matthew 3:7–9). He said, "Even now the axe is laid to the root of the trees. Every tree therefore that does not bear good fruit is cut down and thrown into the fire" (Matthew 3:10).
God, the owner, has been patient with Israel. Hundreds of years prior the prophet Joel said, "Return to the LORD your God, for he is gracious and merciful, slow to anger, and abounding in steadfast love; and he relents over disaster" (Joel 2:13). The parable reflects God's patience as Jesus completes His teaching ministry. Jesus the vinedresser asks for one more year to spread fertilizer—truth that will produce the fruit of good works—and see if the tree will "repent" or change its ways. Presumably, the owner grants his request (Luke 13:8–9).
Some think that the three years reflect Jesus' three-year ministry, others say it means an unspecified amount of time. In the Old Testament, dividing a time span into threes seems to represent a period when things fall into place for a final work, decision, or judgment (Genesis 40:12–13, 18–19; Exodus 15:22–24; 2 Samuel 24:13; 2 Kings 17:5; 18:10; Ezra 8:15, 32; 10:8; Nehemiah 2:11; Daniel 1:5). Jesus uses it again in Luke 13:32–33. In that context, it is interesting that Jesus' ministry and His death and resurrection follow the pattern.