Responsa for Bava Kamma 208:14
אלא מאי לא הודה לא הודה אביו והודה בנו
since the whole discussion revolves here<span class="x" onmousemove="('comment',' In the latter case. ');"><sup>23</sup></span> around the Fifth, does it not show that the principal will have to be paid? It was moreover taught explicitly: 'I would still say that the case where an heir has to pay the principal for a robbery committed by his father was only where both he and his father took oaths or where his father though not he, or he though not his father took an oath, but whence could it be proved that [the same holds good] where neither he nor his father took an oath? From the significant words: <i>The misappropriated article</i> and<i> the deceitfully gotten article, the lost article and the deposit</i><span class="x" onmousemove="('comment',' Cf. Lev. V, 23. ');"><sup>24</sup></span>
Teshuvot Maharam
A. Even A's producing a written consent from the widow would be of no avail unless he can also prove through witnesses that the widow instructed and ordered the writing of the instrument. Should he not be able to do so, he will have to remove the building from the widow's premises and pay her rent for the time his building stood thereon. Should A produce such witnesses, his contract with the widow's son and son-in-law will be non-voidable even though A did not yet pay the rent for the full ten years. Although the widow did not personally instruct her son and son-in-law to rent her premises to A, but sent such instructions in writing — such manner of sending instructions not being acceptable in talmudic law — nevertheless the son and son-in-law became the widow's agents, since it is the usual custom of merchants to accept as valid written instruments, and since the custom of merchants prevails in business transactions.
This Resp. is addressed to R. Eliezer ha-Kohen, and R. Eliezer.
SOURCES: Pr. 698.