for if [it be maintained that it is] that of Rab, a twofold contradiction between Rab's statements would arise. For R. Jeremiah b. Abba laid down on the authority of Rab that if an alley was broken along its full [width] into a courtyard, and a breach was made in the courtyard [wall] over against it, the courtyard is ritually fit but the alley is forbidden. But why [should this be so]? Should it not rather be [subject to the same law] as that of an alley that terminated in a backyard? — The other replied: I do not know, but it once happened that at Dura di-ra'awatha an alley terminated in a backyard, and when I came to Rab Judah [to ask his opinion] he ruled that it required no contrivance whatsoever. If, therefore, a contradiction [arises if Rab Judah's statement] is ascribed to Rab, let it be [conceded to have been made] in the name of Samuel and no difficulty whatever would arise. Now, however, that R. Shesheth said to R. Samuel b. Abba or, as others say, to R. Joseph b. Abba: I may explain to you — [that Rab's ruling is dependent on whether] an ‘erub has been prepared or not, no contradiction between the two statements of Rab does now arise. For one refers to a case where the residents of the courtyard joined in an ‘erub with those of the alley while the other refers to one where they did not join them in an ‘erub.15ᵃᵇᶜᵈᵉᶠᵍʰⁱʲᵏˡᵐⁿᵒ