Reference for Rosh Hashanah 67:3
ומנין ליתן את האמור של זה בזה ושל זה בזה ת"ל שביעי שביעי לגזירה שוה
and again, a day of teru'ah it shall be to you.<span class="x" onmousemove="('comment',' Num. XXIX, 1.');"><sup>3</sup></span> And how do we know that we can utilize what is said in connection with one for purposes of the other and vice versa?<span class="x" onmousemove="('comment',' Two of the verses quoted occur in connection with the New Year and one in connection with the Jubilee. What right have we then to assume from this that there should be three teru'ahs on each?');"><sup>4</sup></span> The word "seventh" occurs twice<span class="x" onmousemove="('comment',' In the seventh month (Lev. XXIII, 24) in connection with New Year, and in the seventh month (Lev. XXV, 9) in connection with the Jubilee.');"><sup>5</sup></span>