Reference for Bava Kamma 18:2

אלא אמר ר' זירא בהידור מצוה עד שליש במצוה

R. Ashi queried: Is it a third from within [the ordinary expense]<span class="x" onmousemove="('comment',' I.e., 33-1/3 per cent. of the cost of ordinary performance, the cost of the ordinary performance and that of the exemplary performance would thus stand to each other as 3 to 4. ');">¹</span>

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