'Purchased' in the Bible

And they *sang a new song before the throne and before the four living creatures and the elders; and no one could learn the song except the one hundred and forty-four thousand who had been purchased from the earth.

These are the ones who have not been defiled with women, for they have kept themselves chaste. These are the ones who follow the Lamb wherever He goes. These have been purchased from among men as first fruits to God and to the Lamb.