Al-Adab Al-Mufrad #992

Ibn Mas'ud said, " They were doing the prayer with the Prophet, may Allah bless him and grant him peace, and someone said, 'Peace be upon Allah.' When the Prophet, may Allah bless him and grant him peace, finished the prayer, he said, 'Who said "Peace be upon Allah"? Allah is Peace. Rather say, "Greetings belong to Allah and good words and prayers. Peace be upon you, O Prophet and the mercy of Allah and His blessings. Peace be upon us and upon all the right-acting slaves of Allah. I testify that there is no god but Allah and I testify that Muhammad is His slave and Messenger."'"