(Mishnah): One may act deceptively with Ma'aser Sheni. How is this? A person may say to his friend, his adult son or daughter or his Jewish servant or maidservant, "Take this money and redeem for yourself this Maaser (Sheni)''.

But he may not say that to his young son or daughter or his Canaanite slave or slave-woman, because their hands are like his.

If a person standing in the threshing floor and he has no money, he may say to his friend, "This produce is yours as a gift'' and he can then say to him, "Behold, these are redeemed onto money in my house''.

(Gemara) (R. Avun): R. Elazar and R. Yosi ben Chanina disagreed - one said that one may act deceptively, because the pasuk uses the word 'blessing' (as it states in Devarim 14:24, "for Hash-m, your G-d, shall bless you...'', indicating that we are not particular if it was redeemed without adding the extra fifth). The other one said, "Why do we redeem it according to its lowest price? As the pasuk states that it is a blessing.

What's the case (where the Mishnah permitted giving the money to another person in order to avoid giving the extra fifth)? If he said to him, "Go and redeem for me'', then he is simply acting as his agent! And if he said, "Go and redeem for yourself'', it belongs to the owner?!

Rather, he said to him, "The produce will be mine and the money yours'' or vice-versa.

Support (Baraisa): If a person said, "The produce will be mine and the money yours'' or "the produce will be yours and the money mine'', he doesn't add the fifth.

(R. Yochanan): For any Maaser that he doesn't own both it and its redemption money, he doesn't add the fifth.

(R. Yosi bei R. Bun citing R. Chanina): R. Yochanan's source is the pasuk that states (Vayikra 27:34), "If a man shall surely redeem from his Maaser, he shall add a fifth of it'' - both it and its money shall be his (in order to need the fifth added).