1. The phrase referred to table fellowship, meaning the giants would eventually join Israel in covenant peace.
2. These giants will be like unleavened bread, easily broken apart.
3. As the manna melted at sunrise, so the Nephilim will melt because the Lord was with them.
4. The Nephilim were so vast in their control over the land and its wealth that they could feed Israel for generations to come.
Option 3 is the answer.
For about one year, the Israelites were sustained daily by manna. One important characteristic of the manna was that it melted when the sun rose (Exodus 16:21). This is why the people had to gather it early each morning, before sunrise.
It is therefore possible that Joshua and Caleb were encouraging Israel with this imagery: just as the manna melted when the sun rose, so the Nephilim would “melt away” when the Lord rose to defend His people. The Lord is later called “the Sun of Righteousness” in Malachi 4:2.
This interpretation may also align with the fear expressed earlier by the people in Deuteronomy 1:28: “Our brethren have made our hearts melt, saying, ‘The people are bigger and taller than we.’”
Israel’s hearts had melted in fear before the giants. But 38 years later, when the Lord arose to help the next generation enter the land, the opposite happened. Rahab declared in Joshua 2:10–11, “When we heard it, our hearts melted, and no courage remained in any man any longer because of you; for the LORD your God, He is God in heaven above and on earth beneath.” At first, Israel melted before the Nephilim. Later, the nations melted before the God of Israel.