Work aimed at another person's hunger moves grief out of a body faster than any amount of waiting.
A decision made before the feelings have settled is the only kind available to someone who has just buried a husband, and moving the body is what changes the state rather than waiting for the state to permit movement. Hunger belonging to somebody else makes a better reason to get up than hunger of one's own, because it cannot be argued with or postponed.
Gleaning sits at the bottom of that whole economy, and taking the lowest rung on purpose is growth where standing still would be decay. Attention fixed on an old woman's next meal has none left over for counting what was lost in Moab. The widow who never goes out keeps her grief at full weight indefinitely.