Tosefta for Sanhedrin 175:12
ועל כולן ב"ש אומרים שלש לעני וארבע לבעל הבית
R. Joshua said: He must warn her in the presence of two, and cause her to drink on the testimony of two.<span class="x" onmousemove="('comment',' Now, instead of submitting to the water ordeal, she could demand a divorce, but without the kethubah (marriage settlement). Hence, if there are no witnesses or only one witness and she demands her divorce, in the opinion of R. Eliezer, she is not entitled to the kethubah, whilst in that of R. Joshua she is. Consequently, if she sold the rights in her kethubah to another man, and the latter seizes the amount involved from the husband, it does not belong to the purchaser, according to R. Eliezer, but does according to R. Joshua; v. p. 579, n. 3. ');"><sup>12</sup></span>