Whenever the Messenger of Allah ﷺ said the opening takbir in prayer, he would remain silent for a moment between the takbir and the recitation. So I said to him, "May my father and mother be ransomed for you, I noticed your silence between the takbir and the recitation. Tell me, what do you say during it?"He replied, "I say, 'O Allah, distance me from my sins as You have distanced the East from the West. O Allah, cleanse me of my sins as a white garment is cleansed of filth. O Allah, wash away my sins with snow, water, and hail.'"
حدثنا أحمد بن أبي شعيب حدثنا محمد بن فضيل عن عمارة ح و حدثنا أبو كامل حدثنا عبد الواحد عن عمارة المعنى عن أبي زرعة
كان رسول الله ﷺ إذا كبر في الصلاة سكت بين التكبير والقراءة فقلت له بأبي أنت وأمي أرأيت سكوتك بين التكبير والقراءة أخبرني ما تقول قال اللهم باعد بيني وبين خطاياي كما باعدت بين المشرق والمغرب اللهم أنقني من خطاياي كالثوب الأبيض من الدنس اللهم اغسلني بالثلج والماء والبرد
Muslim narrated it in the Book of Mosques, chapter on what is said between the takbir of ihram and the recitation, Hadith 598, from the hadith of Muhammad bin Fudayl, and Bukhari, chapter on what is said after the takbir, Hadith 744, from the hadith of Abdul-Wahid bin Ziyad, with the same chain.