Reference for Shevuot 81:6

איכא בינייהו שכנגדו חשוד על השבועה בדאורייתא שכנגדו חשוד על השבועה אפכינן ליה שבועה ושמו אאידך בדרבנן תקנתא היא ותקנתא לתקנתא לא עבדינן

R'Jose says: Real theft.<span class="x" onmousemove="('comment',' Not only in the interests of social stability do we empower the deaf-mute, imbecile, and minor to retain what they find; it is really lawfully theirs; and he who extracts it from them is guilty of real theft.');">⁸</span> And R'Hisda said: [He means] real theft according to their enactment.<span class="x" onmousemove="('comment',' Not real theft according to the Biblical law, but only according to the Rabbinic law.');">⁹</span>

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