why did the story grapes of wrath ended in the barn ?

The final scene in The Grapes of Wrath is one meant to instill some modicum of hope. The debilitated Rose of Sharon breastfeeds the starving man in the barn to sustain him. She gives what was meant for her baby to a complete stranger, an example of selfless sacrifice for the sake of community instead of individual well-being. Yet it took a deep personal loss, the delivery of a stillborn child, to enable Rose of Sharon to aid the man. She cares for the anonymous man with the same love as she would her child, eschewing her selfish individual concerns for a communal good.