Parashas Behar · Aliyah 1 · Passuk 25:10
Chabad.org — English translation + Rashi
Torah Temimah cites Rosh Hashanah 8b.
English: “And you shall sanctify.” It was taught: “And you shall sanctify the fiftieth year” — why is this said? Because it is written “on the Day of Atonement,” one might think it is sanctified only from Yom Kippur onward; the verse says “and you shall sanctify the fiftieth year,” teaching that it is sanctified from its beginning.
Classical derasha (Bavli Rosh Hashanah).
Although the shofar is sounded on Yom Kippur, the sanctity of the fiftieth year begins at the beginning of the year (1 Tishrei).