Reference for Bava Kamma 49:6
ורבנן שבעה דשכינה כתיבי תסגר שבעת ימים
but where it does not defeat the purpose of the <i>a fortiori</i>, even he maintains the principle of <i>Dayyo</i>. In the instance quoted there is no mention made at all of seven days in the case of divine reproof; nevertheless, by the working of the <i>a fortiori</i>, fourteen days may be suggested: there follows, however, the principle of <i>Dayyo</i> so that the additional seven days are excluded, whilst the original seven are retained. Whereas in the case before us<span class="x" onmousemove="('comment',' Regarding compensation whether it be half or full in the case of Horn doing damage. ');"><sup>10</sup></span> the payment of not less than half damages has been explicitly ordained [in all kinds of premises]. When therefore an <i>a fortiori</i> is employed, another half-payment is added [for damage on the plaintiff's premises], making thus the compensation complete. If [however] you apply the principle of <i>Dayyo</i>, the sole purpose of the <i>a fortiori</i> would thereby be defeated.<span class="x" onmousemove="('comment',' V. p. 126, n. 9. ');"><sup>11</sup></span>