פירוש על מעשר שני 4:4

לעבדו ולשפחתו העברים – for their bodies are not purchased (i.e., “owned”)

Introduction When a person redeems his own maaser sheni, he must add an extra fifth to the value, but when he redeems someone else’s maaser sheni produce, he need not do so. Our mishnah teaches that there are ways in which a person can get around having to add the extra fifth, but that this does not always work.

ופדה לך – through them – the Second Tithe for yourself.

One may act in a deceptive manner when it comes to maaser sheni. It is possible to act in a deceptive manner when it comes to maaser sheni so that one can get out of paying the added fifth.

מפני שידן כידו – for what the servant purchased, the Master purchased. And his minor son also, what he possesses and what he finds [belongs] to his father.

How so? A man may say to his grown-up son or daughter, or to his Hebrew slave or female slave, “Take this money and redeem this maaser sheni for yourself.” One is able to give money to one’s adult children or Hebrew slave in order for them to redeem the maaser sheni, as long as he says, “redeem this maaser sheni for yourself.” Even if the child or slave gives the produce back to the father and gives him back the maaser sheni money so that the father can bring it to Jerusalem, this is possible, because adult children and Hebrew slaves are independent of their father/master. These people can independently own property. So this is considered a case of one person redeeming someone else’s maaser sheni, and he does not need to add the extra fifth.

But he may not say so to his son or daughter who are minors or to his Canaanite slave or female slave, because their hand is as his own hand. In contrast, minors and non-Jewish slaves (called Canaanite slaves) cannot legally own property. Any money they make or any thing they find automatically belongs to the father/master. Therefore, when he gives them money to redeem maaser sheni, it is as if he is redeeming it himself, and he still needs to add the extra fifth.