Hazrat Alqamah narrates that once I was present in the service of Hazrat Umar, and our companions said to him, "Teach us whatever you can." Then among the things Hazrat Umar taught us, I remember this: he performed ablution twice and cleaned his nose twice. Then, when he proclaimed the takbeer for prayer, he said these words: "O Allah, You are pure and all praise is for You. Your name is blessed, Your majesty is exalted, and there is no deity except You."