After declaring that Israelites could redeem one another from slavery, but the foreigner would be in permanent slavery, God declares that the same rules do not apply if a foreigner buys an Israelite. If, because of poverty, a rich foreigner buys a poor Israelite, they can be redeemed by a kinsman redeemer at any time. The price of their redemption would decrease depending on the number of years to the Jubilee. Unlike the foreigner, they are released at the year of Jubilee to return to their family. The Israelite also had the responsibility to make sure the foreign master is not being cruel to the Israelite as far as they can tell. All of this is a picture of that true believers might be slaves on this earth, but we are truly free in Christ and will always be free in Him when He returns.