Shaykh Atiq (may Allah have mercy on him) transmitted it with this chain and with the same meaning, and said: "Two stones for the two sides of the buttocks and one stone for the place of passage." Abu al-Hasan al-Daraqutni (may Allah have mercy on him) says: Its chain is hasan (good).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 554