Is it permissible for a Muslim to supplicate to Allah using names other than His, such as "O Most Generous of the generous," knowing that the Beautiful Names of Allah are divinely ordained, and Allah Almighty said: "And to Allah belong the Beautiful Names, so invoke Him by them"?

Allah, the Most High, is the Most Generous of those who show generosity. He says, "Recite, and your Lord is the Most Generous." Thus, "the Most Generous" is one of Allah's Beautiful Names, firmly established by the text of the Holy Qur'an. The addition of "of those who show generosity" is to clarify the object of His name "the Most Generous." Therefore, there is no harm in supplicating to Allah, the Most High, with "O Most Generous of those who show generosity."