Translation:

4. Or a little more; and recite the Qur'an in slow measured rhythmic tones.

Notes (Tafseer)

5756. At this time there was only S. xcvi., S. lxviii, and possibly S. lxxiv, and the opening Sura (Al-Hamd). For us, now, with the whole of the Qur-an before us, the injuction is specially necessary. The words of the Qur-an must not be read hastily, merely to get through so much reading. They must be studied, and their deep meaning pondered over. They are themselves so beautiful that they must be lovingly pronounced in rhythmic tones.