Reference for Shabbat 146:9

והדש: תנא הדש והמנפץ והמנפט כולן מלאכה אחת הן:

R. Abba said: If one digs a pit on the Sabbath, needing only the earth thereof,<span class="x" onmousemove="('comment',' But not the pit itself. ');">¹⁶</span> he is not culpable on its account. And even according to R. Judah, who ruled: One is liable on account of a labour which is not required on its own account:<span class="x" onmousemove="('comment',' V. supra 12a, 31b. ');">¹⁷</span>

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