Reference for Bava Batra 253:9

בשלמא בן ולא טומטום כדר' אמי אלא בכור ולא ספק לאפוקי מאי

[implies] but not a doubtful case.<span class="x" onmousemove="('comment',' That of one about whom it is uncertain whether he is firstborn. ');">²⁹</span> [The statement]. 'in son, but not a <i>tumtum</i>' [can well be explained] in accordance with [the view] of R. Ammi; but what does [the statement]. 'a firstborn, but not a doubtful case', exclude?<span class="x" onmousemove="('comment',' It being obvious that the doubtful first-boris has no claim to the double portion. ');">³⁰</span> — It excludes<span class="x" onmousemove="('comment',' Lit., 'to exclude'. ');">³¹</span> [the opinion arrived at] through Raba's exposition. For Raba gave the following exposition: [if] two women<span class="x" onmousemove="('comment',' Wives of the same husband. ');">³²</span>

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