Reference for Eruvin 176:1

פחות מד' שופכן אי דעביד עוקה שרי אי לא אסור

but in one that is less than four cubits<span class="x" onmousemove="('comment',' Which is hardly worth the trouble of spraying.');">¹</span> he merely pours it out. Hence it is Only if he made a trough<span class="x" onmousemove="('comment',' In which the water may be accumulated and gradually absorbed in the ground.');">²</span>

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