Reference for Gittin 106:12

דר' יהודה אדר' יהודה לא קשיא כי לא קניס בדרבנן בדאורייתא קניס והא מנסך דאורייתא ולא קניס משום חומרא דעבודת כוכבים מיבדל בדילי מיניה

A contradiction was now pointed out between two statements of R. Meir, and also between two statements of R. Judah. For it has been taught: 'If one cooks food on Sabbath, if by inadvertence he may eat it, but if deliberately he may not. So R. Meir. R. Judah says: If [it was cooked] inadvertently he may eat it after the expiration of Sabbath, but if deliberately he may never eat it. R. Johanan ha-Sandalar<span class="x" onmousemove="('comment',' 'The sandal-maker'. ');">⁹</span>

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