Talmud for Bava Metzia 63:2

א"ל מנא לך הא א"ל דתנן אם יש שם ב"ד מתנה בפניהם אין שם ב"ד בפני מי יתנה שלו קודם

or else two witnesses that you did divide in the presence of three [others].'<span class="x" onmousemove="('comment',' In each case the three would constitute a Beth din to ensure that the stock was rightly assessed and a fair division made. ');">²</span>

Jerusalem Talmud Bava Metzia