Shabbos 10:2-3

Shabbos 10:2

If a person brought food from his house and placed it on the threshold, whether he came back and carried it into the public domain or another person did so, he is exempt because he did not perform the entire act all at once. If he put a basket of fruit on the outside threshold, he is exempt even if most of the fruit is on the outside; he is only liable if he carried the whole basket outside.

Shabbos 10:3

If a person transported something between domains, whether in his right hand or his left hand, in his embrace or on his shoulder, he is liable. Carrying on the shoulders is considered a normal method of carrying because that’s how the Levite family of Kehas carried the vessels of the Mishkan (Tabernacle). If one carried on the back of his hand, or with his foot, mouth, elbow, ear or hair, in his belt facing downward, between his belt and his clothes, in the hem of his garment, in his shoe or his sandal, he is exempt because he did not carry in a way that people normally carry.