The Meaning of Aameen
According to majority of the Ulema,
Aameen is an abbreviation of 'Allaahummastajib lana" (Oh Allah!
Accept our Duaa (supplication))
Nabi (Sallallaahu Alayhi Wasallam) had stated: "I have been granted Aameen
(to say) in Salaah and at the time of Du'aa. None was granted such before me
except Moosa(Moses) (Alayhis salaam). He would make Du'aa(supplication) and
Haroon(Aaron) (Alayhis salaam) would say Aameen. So end your Du'aas with
Aameen - Allah will surely answer them for you." (Tafseer Ibn Katheer
Vol.1 Pg.56; Darus salaam). From this Hadith it is apparent that the Jews also
are following the sunnah of their Nabi(Prophet) in saying 'Amen'.
And Allah Ta'ala Knows Best.