Reference for Bava Metzia 164:6
אמר ר' אלעזר תברה מי ששנה זו לא שנה זו ואתא ר' יהודה למימר שומר חנם ישבע נושא שכר ישלם האי כי דיניה והאי כי דיניה ואתא רבי אליעזר למימר אין גמרא כר' מאיר ומיהו תמיה אני אם יכולין זה וזה לישבע
— Said R. Eleazar: Separate them! The two [Baraithas] are not both by the same teacher.<span class="x" onmousemove="('comment',' Lit., 'he who taught this one did not teach the other.' They are irreconcilable and reflect two opposing views on R. Meir's opinion. ');"><sup>10</sup></span> And R. Judah comes to teach that an unpaid bailee must swear, whilst a paid bailee must make it [sc. the damage] good, each in accordance with his own peculiar law.<span class="x" onmousemove="('comment',' On the assumption of the first Baraitha that R. Meir does not regard stumbling as negligence. R. Judah agrees with R. Meir. Consequently the unpaid bailee must swear that there was no negligence; but the paid bailee is responsible for damage caused by stumbling even though it is not accounted as negligence; hence he does not agree with R. Meir that both bailees must swear. ');"><sup>11</sup></span>