The lesson today is about rectitude of intention. The Lord points out the danger in doing good. Such a pitfall happens when we secretly or not so secretly do good expecting the other party to do good to us in return. This may be the minimum to expect in normal and ordinary interpersonalr elationships. But the Lord encourages us to correct that so that we only expect the reward the Lord will give us at the end of our lives. When the good we do to others do not get recognized or requited, we surely are in the right in claiming unfairness. However, Jesus cautions us because such injustice is good for our purification. All the glory to God alone!