Reference for Bava Batra 23:11

דוולא אמר רב נחמן בי דאלו יומא פרדסא אמר אבוה דשמואל בת שלשת קבין

— If you like I can say that a day's ploughing in plough time is meant, and in seed time [it takes a full day] where one ploughs twice,<span class="x" onmousemove="('comment',' Both before and after putting the seed in, and so takes a full day. ');">⁹</span>

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