The Book of Pilgrimage (Kitab Al-Hajj)
Muslim :: Book 7 : Hadith 2970
'Abd al-Rahman b. Yazid reported that 'Abdullah b. Mas'ud (Allah be pleased with them) threw seven pebbles at Jamrat al-'Aqaba from the heart of the valley. He pronounced Takbir with every pebble. It was said to him that people fling stones from the upper side (of the valley), whereupon 'Abdullah b. Mas'ud (Allah he pleased with them) said: By him, besides Whom there is no other god, that is the place (of flinging stones) of one upon whom Surah al-Baqara was revealed (the Holy Prophet).