Translation:Shulchan Aruch/Orach Chaim/16
16: Size of a Shawl.
1 The measurement of a tallit that is obligated in tzitzit is to be covered with it in length and width the head and most of the body of a child who walks by himself in the marketplace and doesn't need someone else to watch him. Gloss: And then it is obligated in tzitzit, and this is precisely that an adult would sometimes wear it in a temporary fashion and go out in it to the marketplace (Beis Yosef in the name of Ben Chaviv and in the name of MHRY"A).