and a split barrel[-shaped defective roofing] rested over them, — then they closed the window with a pitcher and tied a fire pot with a reed rope to ascertain whether the barrel[-shaped roofing] had an opening of a handbreadth or not. AND FROM THEIR WORDS WE LEARN THAT WE MAY STOP UP [A SKYLIGHT] AND MEASURE AND TIE ON THE SABBATH. 'Ulla visited the home of the Resh Galutha and saw Rabbah b. R. Huna Sitting in a bath-tub of water and measuring it. Said he to him: Say that the Rabbis spoke thus of measuring in connection with a precept; did they rule [thus] when it is not in connection with a precept? — I was merely occupying myself, he replied.