Reference for Shabbat 293:3
אביי הוה קאי קמיה דרב יוסף א"ל הב לי כומתאי [חזא דאיכא] טלא עליה הוה קמחסם למיתבה ליה א"ל נפוץ שדי אנן לא קפדינן מידי
R. Isaac b. Joseph said in R. Johanan's name: If one goes out on the Sabbath with a cloak folded up [and] lying on his shoulders, he is liable to a sin-offering.<span class="x" onmousemove="('comment',' The part which is thrown over the shoulder is considered a burden. ');"><sup>4</sup></span> It was taught likewise: Clothes vendors who go out on the Sabbath with cloaks folded up [and] lying on their shoulders are liable to a sin-offering. And they [the Sages] said this not of clothes vendors alone but of all men, but that it is the nature of merchants to go out thus. Again, if a shopkeeper goes out with coins bound up in his wrapper, he is liable to a sin-offering. And they said this not of a shopkeeper alone but of all men, but that it is a shopkeeper's nature to go out thus. And runners may go out with the scarfs on their shoulders;<span class="x" onmousemove="('comment',' These were swift runners, e.g., for carrying express messages. In T.A. I, p. 603, n. 530b, it is conjectured that the [H] (scarf) was their only garment, apart from a loincloth. ');"><sup>5</sup></span>