Musannaf Ibn Abi Shayba 22:211

Zayd ibn al-Hubab narrated to us, from Hammad ibn Salamah, from Ali ibn Zayd ibn Jud'an, from Abd al-Rahman ibn Abi Bakr, from his father, that Gabriel said to the Prophet, may Allah bless him and grant him peace: "Recite the Quran in one mode." Michael said to him: "Ask him for more." He said: "Two modes." Then he said: "Ask him for more," until it reached seven modes. All of them are sufficient and adequate, like your saying "come here" (halumma) and "come" (ta'ala), as long as you do not seal a verse of mercy with a verse of punishment, or a verse of punishment with a verse of mercy.