مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3917
Musnad of Abdullah bin Mas'ood
It was narrated from 'Abdur-Rahman bin Yazeed that 'Abdullah bin Mas'ood went to the bottom of the valley and stood perpendicular to the Jamarat. putting the mountain behind his back, then he stoned (the Jamarat) and he said. This is the place where the one to whom Sooratal-Baqarah was revealed stood.
Musnad Ahmad 3942A saheeh hadeeth, Muslim (1296)]