Anas was asked how the Prophet ﷺ used to recite. He replied, "He used to recite with elongation." Then he recited "In the name of Allah, the Most Gracious, the Most Merciful" [Fatihah 1:1], elongating "Bismillah," elongating "ar-Rahman," and elongating "ar-Rahim."
سئل أنس كيف كانت قراءة النبي ﷺ فقال: كانت مدا ثم قرأ: {بسم الله الرحمن الرحيم} يمد ببسم الله، ويمد بالرحمن، ويمد بالرحيم.