It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (ﷺ) lifted the curtain of his chamber (and saw that) the people were praying behind Sayyiduna Abu Bakr (may Allah be pleased with him). He (ﷺ) said: "Beware! I have been forbidden from reciting the Qur'an in bowing and prostration. In bowing, glorify the greatness of your Lord «سُبْحَانَرَبِّيَالْعَظِيمِ» and in prostration, make abundant supplication, for this is the state in which supplications are most likely to be accepted."
Hadith Referenceالسنن المأثورة / باب ما جاء في القراءة في الركوع والسجود / 159
Hadith Takhrijصحیح مسلم، الصلاة، باب النهي عن قراءة القرآن في الركوع والسجود، رقم: 479