Sforno on Exodus 14:5/ספורנו על שמות י״ד:ה׳

1כי ברח העם, they had not marched straight into the desert as they had maintained they would. In 8,23 all they had asked for was to be allowed to march into the desert a distance of three days’ journey. They had now departed from their planned route so that this could be interpreted as an attempt to flee. The new route made no sense, showing they did not know where they were headed, just as one would expect of a fugitive.

2ויהפך לבב פרעה, Pharaoh had concluded that the Baal Tzefon was an equal to G’d and could frustrate His designs.

3מה זאת עשינו כי שלחנו, what (a foolish thing) have we done in dismissing the Israelites, etc.! We should have consulted Baal Tzefon who would have helped us so that we would have had no need to let the Israelites depart.