פירוש על קידושין 30:10

The phrase “by these” is used to offer some limitation. The words indicate that some sort of redemption leads to freedom and some sort does not.

Rather, the Talmud suggests that their dispute is due to differing assessments of psychology. R. Yose Hagalili argues that by allowing the slave to remain in servitude, we are encouraging Jews to redeem him from non-Jews. In contrast, R. Akiva argues that if he were to go free when redeemed by relatives, he would just sell himself into slavery over and over again, knowing that a relative would redeem him and he would go free.