Jesus is watching with his disciples as people put money into the temple treasury.
When a poor widow puts in two small coins he draws their attention to it - see her total faith in God, her trust. She has aligned herself completely with God's kingdom.
As Ruth did when she came alongside Naomi, leaving her past loyalty and support behind and relying on the God of Israel (under whose wings she sought protection).
The stranger and the widow - Ruth and Naomi both - are God's special care and comfort.
(Many give out of their prosperity. The widow's offering is her faith not her surplus wealth.)