וְקִדַּשְׁתֶּ֗ם אֵ֣ת שְׁנַ֤ת הַחֲמִשִּׁים֙ שָׁנָ֔ה וּקְרָאתֶ֥ם דְּר֛וֹר בָּאָ֖רֶץ לְכָל־יֹשְׁבֶ֑יהָ יוֹבֵ֥ל הִוא֙ תִּהְיֶ֣ה לָכֶ֔ם וְשַׁבְתֶּ֗ם אִ֚ישׁ אֶל־אֲחֻזָּת֔וֹ וְאִ֥ישׁ אֶל־מִשְׁפַּחְתּ֖וֹ תָּשֻֽׁבוּ׃
And ye shall hallow the fiftieth year, and proclaim liberty throughout the land unto all the inhabitants thereof; it shall be a jubilee unto you; and ye shall return every man unto his possession, and ye shall return every man unto his family.
Zohar
R' Yehuda says: From the day Yisrael left Egypt till the day the Torah given was five days. What is the reason? R' Yehuda says: Because they are the years of the Yovel, as it is written (Vayikra 25:10) "You shall sanctify the fiftieth year".