The answer is: Winnowing barley

Ruth 3:2

In the book of Ruth, the threshing floor symbolizes a pivotal place for both agricultural and social transformations. As Boaz was winnowing barley, he was not just engaging in the mundane tasks of harvest; this was a cultural hotspot ripe with possibilities for connection, decisions, and divine encounters. Winnowing was the process of separating the grain from the chaff, making it a fitting metaphor for divine providence—separating the significant from the insignificant.

Interestingly, Ruth's choice to approach Boaz at this specific time and place shows her cleverness and bravery. The harvest season was inherently tied to celebrations and gatherings which allowed Ruth to interact more freely with Boaz, a notable figure in Bethlehem. In the original Hebrew culture, the threshing floor was a male-dominated space of commerce and kinship, yet Ruth, a Moabite widower, navigated this atmosphere with confidence—a testament to her resourcefulness.

Exalted so often as one who displays "hesed" or loving-kindness, Ruth’s bold actions lead to something profound: her integration into the lineage of David, illustrating the concept of inclusion rights that God has for all people. Thus, the events at the threshing floor initiate a ripple that echoes throughout biblical history, culminating in Union—symbolizing a true merge beyond bloodlines. Their story reminds us that beautiful blessings often emerge from the unlikeliest of encounters at the crossroads of courage and heart’s intention.