Sforno on Numbers 13:24/ספורנו על במדבר י״ג:כ״ד

1על אודות האשכול אשר כרתו משם בני ישראל. The Canaanites were surprised about these Israelites who considered this cluster of grapes as something so extraordinary that they cut it off the vine and transported it all the way to their people without bothering to eat it. They were well aware that their country produced far bigger clusters of grapes than the one the spies had taken. The name נחל אשכול reflects the Canaanites’ amazement and who named the location thus.