The last plague but one, like those which had preceded it, endured seven days. All the time the land was enveloped in darkness, only it was not always of the same degree of density. During the first three days, it was not so thick but that the Egyptians could change their posture when they desired to do so. If they were sitting down, they could rise up, and if they were standing, they could sit down.
On the fourth, fifth, and sixth days, the darkness was so dense that they could not stir from their place. They either sat the whole time, or stood; as they were at the beginning, so they remained until the end. The last day of darkness overtook the Egyptians, not in their own land, but at the Red Sea, on their pursuit of Israel. The darkness was not of the ordinary, earthly kind; it came from hell, and it could be felt.
It was as thick as a dinar, and all the time it prevailed a celestial light brightened the dwellings of the children of Israel, whereby they could see what the Egyptians were doing under cover of the darkness. This was of great advantage to them, for when they were about to go forth from the land, and they asked their neighbors to lend them raiment, and jewels of gold and jewels of silver, for the journey, the Egyptians tried to deny having any in their possession.
But the children of Israel, having spied out all their treasures during the days of darkness, could describe the objects they needed with accuracy, and designate their hiding-places. The Egyptians reasoned that the words of the Israelites could be taken implicitly as they spoke them, for if they had had any idea of deceiving them, asking for a loan when they intended to keep what they laid hands on, they might have taken unobserved during the days of darkness whatever: they desired. Hence the Egyptians felt no hesitation in lending the children of Israel all the treasures they asked for.