Reference for Yevamot 144:16
מאי טעמא דרבנן דכתיב (במדבר יט, יז) ולקחו לטמא מעפר שריפת החטאת הנך דפסלי באסיפה פסולין בקידוש הנך דכשרין באסיפה כשרים בקידוש
are permitted to perform sanctification,<span class="x" onmousemove="('comment',' V. supra p. 491. n. 9. ');"><sup>52</sup></span> with the exception of the deaf, the imbecile and the minor. R. Judah permits in the case of the minor but regards a woman and an hermaphrodite as unfit.<span class="x" onmousemove="('comment',' Parah V, 4. ');"><sup>53</sup></span> What is the Rabbi's reason? — Because it is written, And for the unclean they shall take of the ashes of the burning of the purification from sin,<span class="x" onmousemove="('comment',' Num. XIX, 17. ');"><sup>54</sup></span> those who are ineligible<span class="x" onmousemove="('comment',' Minors. ');"><sup>55</sup></span>