→Obligation of Zimmun
# One should say [[Al Neharot Bavel]] before [[benching]] after a meal and on days when there’s no [[tachanun]] one should say [[Shir HaMaalot]] BeShuv Hashem instead. The minhag is to say [[Shir HaMaalot]] at Seudot mitzvah as well. <
Ref> Kitzur Shulchan Aruch 42:5 , Mishna Brurah 1:10,11, Piskei Teshuvot 181:14 in footnote 60. See also [http://www.yutorah.org/lectures/lecture.cfm/744860/Rabbi_Aryeh_Lebowitz/Ten_Minute_Halacha_-_Al_Naharos_Bavel_and_Shir_Hama'alos Rabbi Aryeh Lebowitz on the Ten Minute Halacha].</ref>
==Obligation of Zimmun==
# If three people eat together are obligated to make a Zimmun before [[benching]] (making [[Birkat HaMazon]]). <ref> S”A 192:1 </ref> Chazal based it on the pasuk “גדלו לה" אתי ונרוממה
ה" יחדיו” <ref> Tehilim 34 </ref> and “כי שם ה" אקרא הבו גודל לאלוקונו” <ref> Devarim 30. Gemara [[Brachot]] 45 quoted by the Mishna Brurah 192:1. </ref>.
# Most authorities consider Zimmun to be a rabbinic obligation. <ref> Pri Megadim (A”A 197:2) writes that most authorities consider zimmun to be of rabbinic obligation. Chaye Adam 48:1 writes that Zimmun is derabbanan and some say it’s Deoritta. Chazon Ish (31:1) argues that Zimmun should be Deoritta. </ref>
# Zimmun could be said in any language as the purpose is to introduce the [[benching]] orally and join the group together to praise Hashem. <ref> Zohar (Balak pg 186b) writes that it’s important to precede [[benching]] with “give us a cup to bench” in Hebrew or Aramaic to introduce the [[benching]] to bring the [[kedusha]]. Mishna Brurah 192:2 quotes this and writes the minhag ashkenaz was to say Zimmun in Yiddish “Rabbotei Mir Velin Benchin”. Kol Bo (Siman 25) emphasizes the group merit of the zimmun. </ref>