Abdur Rahman bin Yazid (may Allah have mercy on him) says that Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) stood in the lower part of the valley (the bottom of the valley) and threw pebbles. So I said: O Abu Abdur Rahman! Some people throw pebbles from the upper part of the valley. He replied: By Him besides whom there is no deity, this (the bottom of the valley) is the very place where those people stood (at the time of throwing pebbles) upon whom Surah Al-Baqarah was revealed (peace and blessings of Allah be upon him).