Reference for Gittin 105:19

מתיב רבי אלעזר העושה מלאכה במי חטאת ובפרת חטאת פטור מדיני אדם וחייב בדיני שמים ואי אמרת היזק שאינו ניכר שמיה היזק בדיני אדם נמי לחייב

— This in fact is what is meant: 'If they act presumptuously they are liable; from which we infer that if they acted innocently they are not liable, to prevent abuses.' R. Eleazar [raised the following as] an objection: 'If one does work with the waters of purification and with the heifer of purification,<span class="x" onmousemove="('comment',' The 'red heifer': v. Num. XIX. It was forbidden to do any work work with it. ');">¹⁷</span>

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