Responsa for Bava Kamma 83:7
אמר רבא יציבא בארעא וגיורא בשמי שמיא
No, said Raba. [The implication drawn by R. Jose] is essential [for this reason, that] you might have been inclined to apply the inference 'Men but not oxen' only to oxen which could be compared to men — just as men are <i>Mu'ad</i> so the oxen here referred to are <i>Mu'ad</i> — and to have extended the exemption to cases of <i>Tam</i> by an argument <i>a fortiori</i>. Therefore the Divine Law purposely states [further], <i>The owner of the ox shall be quit</i> [to indicate that only] in the case of <i>Tam</i> will there be exemption whereas in the case of <i>Mu'ad</i> there will be liability. Said Abaye to him: If that is so, why not argue in the same way in the case of payment for degradation; thus: [Scripture says] 'Men',<span class="x" onmousemove="('comment',' Deut. XXV, 11. ');"><sup>7</sup></span>
Teshuvot Maharam
A. B must take the oath usually taken by all partners, which is administered by the hazzan holding the Scroll of the law. Although giving one's faithful word is also considered an oath, it is not as solemn as the oath administered while holding the scroll of the Law, and can not take its place.
SOURCES: Cr. 171; Pr. 606; L. 379; Mord. Shebu. 765; cf. Hag. Maim. Shebuoth 11, 3; Moses, Minz, Responsa 17.