IF ONE CARRIES OUT [AN ARTICLE], WHETHER WITH HIS RIGHT OR WITH HIS LEFT [HAND], IN HIS LAP OR ON HIS SHOULDER, HE IS CULPABLE, BECAUSE THUS WAS THE CARRYING OF THE CHILDREN OF KOHATH
That is the Biblical tribe of Levites who had the obligation of carrying by hand some articles of the tabernacle: But to the sons of Kohath he gave [no wagons]; because the service of the sanctuary belonging to them was that they should carry upon their shoulders (Num. 7:8). And the general principle is that the categories of Sabbath laws all relate to the Tabernacle (see Shabbat 49b).
However, the corollary is that those who carry (in public on Shabbat) in a non-standard way are not culpable, because. . .
HE HAS NOT CARRIED [IT] OUT AS PEOPLE [GENERALLY] CARRY OUT
“Non-standard” being, for example:
WITH HIS FOOT, IN HIS MOUTH, WITH HIS ELBOW, IN HIS EAR, IN HIS HAIR, IN HIS BELT WITH ITS OPENING DOWNWARDS, BETWEEN HIS BELT AND HIS SHIRT, IN THE HEM OF HIS SHIRT, IN HIS SHOES OR SANDALS
But, then, we have an interesting controvery:
Rab said on R. Hiyya's authority: If one carries out a burden on his head on the Sabbath, he is liable to a sin-offering, because the people of Huzal do thus.
Are then the people of Huzal the world's majority! Rather if stated, it was thus stated: Rab said on R. Hiyya's authority: if a Huzalite carries out a burden on his head on the Sabbath, he is liable to a sin-offering, because his fellow-citizens do thus.
But let his practice be null by comparison with that of all men?
Rather if stated, it was thus stated: If one carries out a burden on his head, he is not culpable. And should you object, ‘But the people of Huzal do thus’, their practice is null by comparison with that of all men.
More interestingly, it gives an indication that local practice can determine the application of Jewish law. We have to pay attention to what the people are actually doing and modify accordingly; in this case more strictly, other times more leniently. Another example of the flexibility of Jewish law.