[If] two groups were eating in one house: When some of them can see each other, they may combine for a collective blessing; but if not, these conduct a collective blessing by themselves, and these conduct a collective blessing by themselves. We do not recite a blessing over wine until water is added it; [these are] the words of R’ Eliezer. But the Sag-es say: We recite the blessing.

Three who ate together are not permitted to separate. And so too for four, and so too for five. Six may separate, up to ten. But ten may not separate, up to twenty.