Is a prior intention (initially entering with intent to combine) required for two groups to combine for zimun?
Synopsis
The Mechaber's plain text suggests prior intent is required even in one house. Several later authorities dispute this, holding prior intent is only necessary for two houses, not one. The Vilna Gaon and many Acharonim rule prior intent is unnecessary for groups in one house.
More in Zimmun — Joining and Splitting Groups
Can two groups eating in one or two houses combine for a zimun when some members of each group can see one another?
3 opinions
Does a single waiter (shamash) serving both groups suffice to combine them for a zimun, even without mutual visibility?
2 opinions
Does a public domain (reshut harabim) or private path separating two houses prevent combination for zimun?
3 opinions
Does a public domain prevent combination for zimun at a wedding feast (beit hachupa)?
2 opinions
Can groups eating partly inside a house and partly outside combine for zimun, and if so how?
3 opinions
When two groups combine for zimun, how much of the blessing must both groups hear from the leader?
4 opinions
When two groups combine and want the leader to discharge them entirely from Birkat HaMazon, what must they do?
2 opinions
What is the rule b'dieved if someone did not hear the leader's zimun call but heard the responders answering 'Baruch she'achalnu'?
1 opinions
Related from other topics
Must one have kavvanah (intention/concentration) during the Amidah, and which blessings require it?
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If one prayed a second time intending it to be voluntary due to doubt, but then one's intention or conditions change mid-prayer, may one continue praying?
Rain Prayers
If one intentionally (mezid) did not pray, may one make it up in the next prayer?
Missed Prayers
What is the status of a prayer that lacks proper intention at the beginning but is corrected midway?
Missed Prayers
If one intentionally (b'mezid) mentions rain at the wrong time, is the consequence different from inadvertent error (b'shogag)?
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What intention (kavana) should one have when responding Amen?
Repetition of Amidah
Discussion
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