The evening after the ^Id, the pilgrim goes to Mina and spends the night there.
The next day is the first of the Tashriq days.
After the zawal time of the first Tashriq day, the pilgrim goes to throw seven (7) pebbles at each of the three (3) jamrah stations.
He starts with the smallest station, named as-Sughra, which is the pillar next to Masjid al-Khayf, and throws seven (7) pebbles there. Then he goes to the middle one (al-Wusta) and throws seven (7) pebbles there. He ends with the largest (al-^Aqabah or al-Kubra) and throws seven (7) pebbles there. Mixing up this order invalidates every throwing that does not comply with it.
For example, if one throws the pebbles first at the ^Aqabah station, then the middle station, then the Sughra station, only the last throwing is valid and one needs to repeat throwing the pebbles at the middle and the largest stations.
The jamarah stations in Mina are circular basins with pillars as markers.
They are not the residence of the devil as some people think.
Rather, we throw pebbles in these locations, as Prophet Ibrahim threw pebbles at the devil in these locations when he appeared and tried to block Ibrahim from performing the order of Allah to slaughter his son, Isma^il. Throwing the pebbles signifies that if the devil appears to us as he did to Prophet Ibrahim, we will reject and degrade him.
At each pillar-station one throws seven (7) pebbles, by one’s own hand, one by one, making sure that they land in the specified basin. It is sunnah to say “Allahu akbar” while throwing them. It is not permissible for one to authorize another to throw the pebbles on one’s behalf except if one is unable (for a valid excuse) to do so before the end of the third Tashriq day.
On the second day of the Tashriq days, the pilgrim again throws pebbles at the three jamrahs, as he did the previous day. If he stays in Mina until the sun sets on the second day, it becomes an obligation upon him to throw the pebbles at the jamrahs on the third Tashriq day.
It is permissible to delay throwing all the pebbles until the third day, as long as one performs that before sunset, and following the specified order.
If one did not throw at al-^Aqabah on the ^Id day, one would start there, throw seven (7) pebbles, then go to the smallest station and throw seven (7) pebbles. Next, one moves to the middle station and throws seven (7) pebbles there.
Finally, at the largest (al-^Aqabah) one throws seven (7) pebbles. Then one returns to the smallest and repeats the order for the second round, and the same for the third round. All the pebbles must be thrown before the sunset of the third Tashriq day