Leviticus 5:24

בראשו — This means the principal — the capital (ראש) money. וחמשתיו [AND HE SHALL ADD] THE FIFTH PART [MORE THERETO) — By using the plural וחמשתיו the Torah includes in this law of restitution the many additional fifths possible in respect to one principal — that if he denies the fifth (i. e. he asserts that he has repaid both capital and fifth, but has not really paid the latter, for which a claim is now made against him) and takes an oath that he has paid it, but afterwards admits the claim, then he must now bring (pay) a fifth in addition to this fifth (a fifth of the original fifth which now has become the קרן in addition to it), and so he keeps on adding a fifth to the original fifth until the principal about which he takes an oath becomes less in value than a P’rutah (Sifra, Vayikra Dibbura d'Chovah, Section 13 12; Bava Kamma 103a). לאשר הוא לו [AND HE SHALL ADD THE FIFTH PART MORE THERETO AND GIVE IT] UNTO HIM TO WHOM IT APPERTAINETH — i. e. to him whose is the money (Sifra, Vayikra Dibbura d'Chovah, Section 13 12; Bava Kamma 108; also Bava Kamma 103a).

א֠וֹ מִכֹּ֞ל אֲשֶׁר־יִשָּׁבַ֣ע עָלָיו֮ לַשֶּׁ֒קֶר֒ וְשִׁלַּ֤ם אֹתוֹ֙ בְּרֹאשׁ֔וֹ וַחֲמִשִׁתָ֖יו יֹסֵ֣ף עָלָ֑יו לַאֲשֶׁ֨ר ה֥וּא ל֛וֹ יִתְּנֶ֖נּוּ בְּי֥וֹם אַשְׁמָתֽוֹ׃

or all that about which he has sworn falsely; he shall even restore it in the principal, and shall add the fifth part more to it, and give it to him to whom it belongs, in the day of his trespass offering;