Machshirin 6:1-2

Machshirin 6:1

If someone took his produce to the roof to rid it of maggots and dew formed on it, ki yutan doesn’t apply; if his intention was that the dew would moisten his produce, then ki yutan does apply. If a person with congenital deafness, a person lacking mental faculties or a minor brought the produce to the roof, ki yutan doesn’t apply even if they intended that the dew moisten it. This is because their actions are efficacious but their intentions aren’t.

Machshirin 6:2

If someone took bundles of vegetables, of unprocessed figs or of garlic to the roof so that they should moisten (from the air), ki yutan doesn’t apply (if dew forms on them). All bundles of vegetables in the market are ritually unclean, though Rabbi Yehuda rules fresh bundles ritually clean. Rabbi Meir said the Sages ruled bundles of vegetables unclean because of the moisture found in one’s mouth (that vendors would sometimes use to clean vegetables). All the different kinds of coarse and fine flour in the market are ritually unclean. Wheat grains split into two, three or four parts are unclean everywhere (not just in markets).