# the abundance of their joy and the extremity of their poverty have produced great riches of generosity

"because of the people's great joy and extreme poverty, they have become very generous" 

# the abundance of their joy

Paul speaks of joy as if it were a physical object that could increase in size or quantity. 

# extremity of their poverty ... riches of generosity

Though the churches of Macedonia have suffered testings of affliction and poverty, by God's grace they have been able to collect money for the believers in Jerusalem. The churches in Macedonia also had given generously. Paul sends Titus and two other believers to Corinth to encourage the Corinthians to give generously. Paul and the others will carry the money to Jerusalem. They want people to know it is being done honestly.

# great riches of generosity

"a very great generosity."