Reference for Chullin 135:19

הוציא את ראשו אף על פי שהחזירו הרי זה כילוד תנא נמי רישא

'Who is considered a firstborn for the right of inheritance<span class="x" onmousemove="('comment',' To be entitled to a portion in the inheritance twice as much as any one of his brothers. Deut. XXI, 17.');">⁸</span>

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