Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said: We said: "O Messenger of Allah (peace and blessings be upon him), these stones with which stoning is done are taken away; it is thought that they are being cut away." He (peace and blessings be upon him) said: "Whatever is accepted is taken up. Were it not so, you would see them like mountains."
Yazid bin Sinan is not strong in hadith, and it has also been narrated as marfu' from Ibn Umar through another weak route.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9545