Before stoning the Jamarat, say 'Bismillah, Allahu Akbar' with each pebble thrown. Nabi stopped reciting the Talbiyah upon reaching Jamrat al-Aqabah and began stoning. Say 'Allahu Akbar' with each of the seven pebbles. After the small and middle Jamarat (on Days of Tashriq), stand facing the Qiblah and make lengthy doa.
بِسْمِ اللَّهِ، اللَّهُ أَكْبَرُ، اللَّهُمَّ اجْعَلْهُ حَجًّا مَبْرُورًا وَذَنْبًا مَغْفُورًا
Bismillah, Allahu Akbar. Allahumma-j'alhu hajjan mabruran wa dhanban maghfura.
Meaning: In the name of Allah, Allah is the Greatest. O Allah, make it an accepted Haji and a forgiven sin.
Source: Sahih Muslim #1218The stoning of the Jamarat symbolizes the rejection of Shaytan, commemorating Prophet Ibrahim's (shallallahu alaihi wa sallam) rejection of Iblis when he tried to dissuade him from obeying Allah's command to sacrifice his son. Each pebble thrown with 'Allahu Akbar' is a declaration that Allah is greater than all temptation and disobedience. Nabi instructed that pebbles should be small, like date stones.
بِسْمِ اللَّهِ، اللَّهُ أَكْبَرُ، اللَّهُمَّ اجْعَلْهُ حَجًّا مَبْرُورًا وَذَنْبًا مَغْفُورًا
The Prophet (peace be upon him) came to Jamrat al-Aqabah and threw seven pebbles, saying 'Allahu Akbar' with each pebble — pebbles the size of date stones. He threw from the bottom of the valley.