Shulchan Arukh, Orach Chayim 518/שולחן ערוך·אורח חיים תקי״ח

1Since carrying was permitted for the sake of food preparation, it was also permitted for the sake of non-(food preparation), such as (for the sake of) a minor, a Lulav, a Sefer Torah, and vessels. Rema: (Provided) that one needs them a bit, or if one is afraid lest they be stolen or suffer some other loss (Hagahot Semak & R. Yerucham) but (carrying) stones and the like is prohibited. Rema: And it is permitted to play with a ball, even in the public domain, despite the fact that it is mere recreation (Tosafot & R. Yerucham). And if one established a "eruv" it is permitted to handle and carry anything that is considered a vessel, even though it has no need that day at all (Ran, Beitzah Chapter 2).