Reference for Bava Batra 217:3
אימא שארו זה האב מלמד שהאב קודם לבת יכול יקדים לבן ת"ל הקרוב קרוב קרוב קודם
— The very [law of a son's precedence in the case of the redemption of a] field of [his father's] possession was deduced by the Tanna from this very argument, viz., 'Surely levirate marriages only take place where there is no son, but where there is a son there is no levirate marriage'!<span class="x" onmousemove="('comment',' It was this argument that had confirmed the Tanna in his opinion that a son takes his father's place in the redemption of a field of his father's possession (v. 'Ar, 25b). Without this argument it could not have been proved that a son has any greater claim to the redemption of the field than a brother or any other person. Since this law, then, depends entirely on the argument mentioned, there remains only one independent point in favour of a son's precedence. Hence it was necessary to have recourse to the reply mentioned. ');"><sup>5</sup></span> [But why not] say [thus]: <i>'His kinsman</i>,<span class="x" onmousemove="('comment',' Num. XXVII, 22. ');"><sup>6</sup></span>