Oneness, Uniqueness of Allah (Tawheed)
Bukhari :: Book 9 :: Volume 93 :: Hadith 645
Narrated Ibn 'Abbas:
The delegates of 'Abdul Qais came to Allah's Apostle and said, "The pagans of the tribe of Mudar intervene between you and us therefore we cannot come to you except in the Holy months. So please order us to do something good (Religious deeds) by which we may enter Paradise (by acting on them) and we may inform our people whom we have left behind to observe it." The Prophet said, "I order you to do four things and forbid you from four things: I order you to believe in Allah. Do you know what is meant by belief in Allah? It is to testify that none has the right to be worshipped except Allah, to offer prayers perfectly, to give Zakat, and to give Al-Khumus (one-fifth of the war booty) (in Allah's Cause). And I forbid you four things, (i.e., Do not drink alcoholic drinks) Ad-Dubba, An-Naqir, (pitched water skins), Az-Zuruf, Al-Muzaffat and Al--Hantam (names of utensils used for the preparation of alcoholic drinks)." (See Hadith No. 50, Vol. 1)