Jamarah is a pillar at which the pilgrim is to pelt with pebbles. There are three such pillars: Al-Jamarah Al-Ula [The first stone pillar], Al-Jamarah Al-Wusta [The second (middle) stone pillar], and Jamarat Al-`Aqabah [The last and largest stone pillar]. There is nothing wrong if a pilgrim throws a pebble at one Jamarah before the other. He is not required to offer a sacrifice or any kind of expiation.
Sheikh `Abdul-Bari Az-Zamzami, a member of the Moroccan Scholars’ Association, states: There is nothing wrong in what this man did. What is required of him is to throw the pebbles. If he threw one before the other due to forgetfulness, his throwing of the pebbles is still valid and he is not required to offer any kind of expiation or slaughter a hadi (sacrificial animal) for that reason. The same holds true if one has his head shaved before slaughtering the hadi or if he slaughtered the hadi before doing the tawaf. When the Prophet (peace and blessings be upon him) was asked about anything (regarding the ceremonies of Hajj) performed before or after its due time, his reply was: “Do it (now) and there is no harm.”