The last mishna of the sixth chapter of N'darim reads, in part:

מן המקפה אסור בשום

This means that if someone declared that mikpa is forbidden for own his use as sacrificial offerings are, then he can't use garlic either. The commentaries explain that mikpa was a cooked dish of legumes or something like that, and it customarily contained garlic for taste.

I don't understand why the garlic is forbidden. Just because mikpa customarily contained it? If someone forbade chicken soup for his own use, would he not be allowed garlic or onion — or water? I suspect I'm missing something here.

(The Rav (Bartinura) explains:

רגילים היו לתת שום בכל מקפה כדי שיתן טעם והשום הוא המקפה

 

They were accustomed to put garlic in every mikpa to provide taste, and the garlic is the mikpa.

I suspect that in those last words lies the answer to my difficulty above, if I could but understand them, but I can't.)

The last mishna of the sixth chapter of N'darim reads, in part:

מן המקפה אסור בשום

This means that if someone declared that mikpa is forbidden for own his use as sacrificial offerings are, then he can't use garlic either. The commentaries explain that mikpa was a cooked dish of legumes or something like that, and it customarily contained garlic for taste.

I don't understand why the garlic is forbidden. Just because mikpa customarily contained it? If someone forbade chicken soup for his own use, would he not be allowed garlic or onion — or water? I suspect I'm missing something here.

(The Rav (Bartinura) explains:

רגילים היו לתת שום בכל מקפה כדי שיתן טעם והשום הוא המקפה

They were accustomed to put garlic in every mikpa to provide taste, and the garlic is the mikpa.

I suspect that in those last words lies the answer to my difficulty above, if I could but understand them, but I can't.)