משנה אויף במדבר 5:7

Fraud is four pieces of silver. A claim is [a minimum] of two pieces of silver. An admission is [a minimum] of that which is worth a perutah. There are five [rules involving] that which is worth a perutah: An admission is [a minimum] of that which is worth a perutah. A woman can be betrothed with that which is worth a perutah. Someone who benefits a perutah’s worth from that which belongs to the sanctuary has committed sacrilege. One who finds that which is worth a perutah must proclaim it [as a lost object]. One who steals that which is worth a perutah from his fellow and swears [falsely] to him [that he did not steal it], must go after him [to return it] even as far as Medea.

If he had paid him the value and had sworn [falsely] to him concerning the [added] fifth, he must pay a fifth on the fifth [and so on] until the value [of the added fifth] becomes less than a perutah’s worth. So too with a deposit, as it says: “In a matter of deposit or a pledge or through robbery, or by defrauding his fellow, or by finding something lost and lying about it” (Leviticus 5:21-2, such a one must pay the value and the [added] fifth and bring a Guilt-offering. [If a man said], “Where is my deposit?” and the other said, “It is lost,” [if the one says,] “I adjure thee”, and the other says, “Amen!”, and witnesses testify against him that he consumed it, he need pay [only] the value. But if he confessed it of himself, he must repay the value and the [added] fifth and bring a Guilt-offering.