967. The Food to Be Used for an Eiruv

Eiruvin 6:7

Any food that can be used to make a shittuf can also be used to make an eiruv techumin. Conversely, any foods that cannot be used for a shittuf cannot be used for an eiruv techumin. The minimum volume of food needed for an eiruv techumin is enough for two meals per person. If the food being used is a side dish, it must be enough of that food to accompany two meals, the same as with a shittuf.

Eiruvin 6:8

The place where one will spend Shabbos and the location of his eiruv must be in the same domain so that it would be potentially possible for him to eat it during the twilight period. Therefore, if one intends to spend Shabbos in a public domain but he places his eiruv in a private domain, or vice versa, the eiruv is not valid because it is not possible to transfer between a private domain and a public domain without violating Shabbos.