"When he looked up he saw some wealthy people putting their offerings into the treasury and he noticed a poor widow putting in two small coins. He said, "I tell you truly, this poor widow put in more than all the rest; for those others have all made offerings from their surplus wealth, but she, from her poverty, has offered her whole livelihood." Lk 21:1-4 NAB. (See footnote 1, compare NIV, and Mark 12:41-42.) (The NIV suggests these coins are Lepta, small copper coins similar to a penny.)
Jesus does not say the wealthy are wrong to donate, he points out how God values each of these gifts. Again, God does not think or act or value the way people do. In our "normal" world, when a large donation is made, the recipient always responds with great praise and gratitude. The amount of the gift is important and if the giver is wealthy the recipient wants to cultivate the donor so as to encourage additional donations, especially large ones. God does not act this way and in fact he warns people to avoid appearing generous in order to receive praise. Matt. 6:1-4 NAB and footnotes 1 and 2.
God is not impressed with someone who gives only out of his surplus wealth. Again, it is not wrong to do so only not particularly virtuous either. Modern people seem to think that any gift is virtuous, however, Christian and catholic tradition speak of alms, charity (see Love for Poor), and support of the church (CCC 2043) as duties. Jesus acknowledges and praises the widow because she goes beyond mere duty.
God realizes the magnitude of her gift, and the magnitude of her faith. A widow in her time and place could not work. She was dependent on a male relative for support*. Jesus implies that she has no home, no food, no means of support when he says she "has offered her whole livelihood". She is surrendering to God all she has, trusting God to provide all she needs.
In doing this, she is in complete contrast to the rich young man. Mark 10:17-31; Matt. 19:16-30. He was unable to come to this level of faith and trust in God, whose story gives Jesus an opportunity to warn the rich of the danger they are in. The widow and the beggar Lazarus (Lk 16:19-31) are in an advantageous position because of their poverty. Her story is more instructive than Lazarus's. She demonstrates not only poverty but also generosity and trust.
*"A widow is already bereft of her husband, the male in whom she was embedded. If her eldest son was not yet married, she was even more disadvantaged. And if she had no sons at all, she might have to return to her family of origin (see Lev 22:13; Ruth 1:8) if that were still possible... Because widows were not included in Hebrew inheritance laws, their constant concern was simply living from day to day. Any resources this widow had were meager at best." John J. Pilch of Georgetown University. Pilch goes on to assert that in her culture it was taken for granted that one did not do something that reduces one's status. Therefore, the widow's gift would be viewed by her contemporaries as being scandalous. However, God values things differently. Nevertheless caution is warranted. No one should deprive someone so poor of all she has, even for charity. Her action may be praiseworthy but the recipient's may not be. The Cultural World of Jesus, Sunday by Sunday, Cycle B, John J. Pilch. The Liturgical Press. 1996. pp. 160-162.
The welfare of widows was a concern of the early church. James 1:27; 1 Timothy 5:3.