Commentary for Kiddushin 30:5

Rabbi reads the words “by these” as teaching that a slave purchased by a Gentile does not go free after six years. In contrast, two other tannaim read the phrase as teaching something different. R. Yose the Galilean reads them as teaching that if a relative redeems the slave, he goes free. But if he is redeemed by a non-relative, then he becomes a slave to that redeemer. R. Akiva reads this opposite—if he is redeemed by the relative, then he remains a slave. If by any other man, then he goes free.