There are two elements in the severance gift: 1) the master has an obligation to show gratitude for the time and effort given to him by the slave. This gift must be generative, so that his gratitude will continuously be shown even after the slave begins his own life. 2) The slave’s freedom is complete when he experiences the reverse from his previous state of poverty. When he receives an abundance of gifts, he is truly free. From the perspective of the slave’s freedom, the kind of gift is not important, only the abundance of it.
This is why the spoils of the sea, and Yosef’s language learning, were considered severance gifts. These may not fulfill the owner’s obligation of expressing gratitude, but they do fulfill the role of completing the freedom of the slave, by gifting them with an abundance of wealth (spoils or, in Yosef’s case, knowledge).
This is why the verse does not mention the details of the Jewish people’s severance gift, but simply says, “and G-d redeemed you.” Included in this act of redemption are the gifts given to the Jewish people which completed their experience of redemption and freedom.
