Reference for Bava Batra 90:3

מאי שנא רישא ומאי שנא סיפא

if a man entrusts an article to another in the presence of witnesses, he must return it in the presence of witnesses.<span class="x" onmousemove="('comment',' Therefore he cannot plead, 'I returned it to you,' nor, consequently, 'I bought it'. ');">³</span>

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