Exodus 3:21
And I will give this people favour in the sight of the Egyptians: and it shall come to pass, that, when ye go, ye shall not go empty: And I will give this people favour in the sight of the Egyptians: and it shall come to pass, that, when ye go, ye shall not go empty:
God would give Israel favor in the sight of the Egyptians through the powerful works and miracles He wrought for their deliverance, so that the Egyptians would grant their requests and Israel would not go out empty-handed when they left Egypt. Not going empty meant every woman was to ask for jewels of silver and of gold and for clothing to put upon sons and upon daughters, articles of silver and gold and clothing portable enough to be carried on the journey. The neighbor and the one lodging in the house, described as sojourner, means the Egyptian set over Israel to enforce the daily amount of labor, from whom the amount was to be asked. Receiving these valuables in this way would spoil the Egyptians.
The goods were needed for the long journey, to exchange for bread and to use as circumstances required. Taking the goods, even quite a large amount, was right and was only a small recompense for years of hard labor unjustly extorted. Egypt had enslaved a people who were not slaves and had no right to their labor, giving them only sustenance while enriching itself by their labor under oppression and heavy burdens until God acted to interpose for them.