Hadith 1076
Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Jibreel (peace be upon him) taught me one mode (harf), but I kept asking for more, so he kept granting me until it reached seven modes." Zuhri says: The meaning of seven modes is that as long as they remain in the same meaning, and there is no change in what is lawful and unlawful.
Hadith 1077
It is narrated from Sayyiduna Ubayy bin Ka'b, may Allah be pleased with him, that the Noble Prophet, peace and blessings be upon him, said: "Jibreel (Gabriel), peace be upon him, said that recite the Qur'an in seven modes."