Targum zu Schemot 12:37

And the sons of Israel moved forth from Pilusin towards Succoth, a hundred and thirty thousand, protected there by seven clouds of glory on their four sides: one above them, that neither hail nor rain might fall upon them, nor that they should be burned by the heat of the sun; one beneath them, that they might not be hurt by thorns, serpents, or scorpions; and one went before them, to make the valleys even, and the mountains low, and to prepare them a place of habitation. And they were about six hundred thousand men, journeying on foot, none riding on horses except the children five to every man;