Musar for Rosh Hashanah 34:7
אמר רב יהודה ברית כרותה לי"ג מדות שאינן חוזרות ריקם שנאמר (שמות לד, י) הנה אנכי כורת ברית
A God merciful and gracious:' Rab Judah said: A covenant has been made with the thirteen attributes<span class="x" onmousemove="('comment',' Enumerated in this verse. According to one reckoning, 'The Lord, the Lord' count as two, according to another reckoning only the second of these counts as an attribute, and the expressions 'keeping mercy' and 'unto the thousandth generation' count as two attributes. V. Tosaf., s.v. aka .');"><sup>11</sup></span> that they will not be turned away empty-handed,<span class="x" onmousemove="('comment',' I.e., that Israel will not be turned away empty-handed when they recite them.');"><sup>12</sup></span> as it says, Behold I make a covenant.<span class="x" onmousemove="('comment',' Ibid. 10.');"><sup>13</sup></span>