Sahih Bukhari Volume 8, Book 78, Hadith Number 645.

Narated By Abu Huraira : The Prophet said, “Whoever swears saying in his oath. ‘By Al-Lat and Al’Uzza,’ should say, ‘None has the right to be worshipped but Allah; and whoever says to his friend, ‘Come, let me gamble with you,’ should give something in charity.”