Reference for Yevamot 219:6

אמר רב פפא בנרש מינסב נסיבי והדר מותבי אבי כורסייא רב אשי אמר הוא עשה שלא כהוגן לפיכך עשו בו שלא כהוגן ואפקעינהו רבנן לקידושי מיניה

but that if he did not cohabit with her none is required?<span class="x" onmousemove="('comment',' Lit., 'not'. ');">²²</span> Surely it once happened at Naresh that a man betrothed a girl while she was a minor, and, when she attained her majority and he placed her upon the bridal chair,<span class="x" onmousemove="('comment',' It is assumed that this was a ceremony similar to ordinary huppah (v. Glos.). ');">²³</span> another man came and snatched her away from him; and, though Rab's disciples, R. Beruna and R. Hananel, were present on the occasion, they did not require the girl to obtain a letter of divorce from the second man!<span class="x" onmousemove="('comment',' Obviously because they regarded the first marriage. though no cohabitation had taken place (v. supra n. 10), as valid, As the disciples presumably acted in accordance with the ruling of their Master, Rab, how could it be said that Rab requires a divorce only where cohabitation had taken place? ');">²⁴</span> — R. Papa replied: At Naresh they married<span class="x" onmousemove="('comment',' Cohabitation. ');">²⁵</span> first and then placed [the bride] upon the bridal chair.<span class="x" onmousemove="('comment',' And this is the reason why Rab's disciples regarded the marriage with the first husband as valid and, therefore, required no divorce from the second man. ');">²⁶</span>

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