Why was Pharaoh worried that children of Israel would leave Egypt?

If Pharaoh was worried that the children of Israel were too numerous, why was he concerned about the possibility of them going ‘up from the land’?

• Rashbam suggests that Pharaoh was worried about the land becoming depopulated.
• Sa’adya Gaon, Rashi and Rabeinu Bahya follow a midrashic explanation according to which Pharaoh was expressing in a roundabout way his concern that the children of Israel would force the Egyptians out of the land.
• Ramban suggests that Pharaoh’s concern was that they would join Egypt’s enemies in looting the land and then leave with Egypt’s wealth.

For more on parshat Shemot, see Haggadah Berurah, the Haggadah that helps you tell the story of yetziat mitzrayim.