Reference for Sanhedrin 56:27

אמר רבה בר בר חנה א"ר יוחנן הלכה כר' יוסי הגלילי

A certain deed of gift had been attested by two brothers-in-law. Now, R.Joseph thought to declare it valid, since Rab Judah said in Samuel's name:The <i>halachah</i> rests with R. Jose. But Abaye said to him: How do we know that[he referred to] the ruling of R. Jose as stated in the Mishnah which permitsthe evidence of a brother-in-law: perhaps he meant the ruling of R. Josein the Baraitha, which disqualifies a brother-in-law? — One cannot thinkso, for Samuel said:<span class="x" onmousemove="('comment',' In illustration of a brother-in-law who is disqualified. ');">³⁷</span>

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