Albert Barnes Commentary Ruth 2:17

"So she gleaned in the field until even; and she beat out that which she had gleaned, and it was about an ephah of barley." — Ruth 2:17 (ASV)

And beat out that she had gleaned – Namely, with a stick, as the word implies (Isaiah 27:12). This method is still commonly practiced. Ruth gleaned enough to support herself and her mother-in-law for five days (Exodus 16:16).