A.T. Robertson Commentary John 4:41

"And many more believed because of his word;" — John 4:41 (ASV)

Many more (πολλω πλειους). "More by much" (instrumental case πολλω) in comparison with just "many" (πολλο) of verse 39. Jesus was reaping more rapidly than the woman did. But all were rejoicing that so many "believed" (επιστευσαν, really believed).