Is it permissible to supplicate with the words: "O Allah, make me pure" during prayer?

Nothing appears to prevent the aforementioned supplication, as purity includes both sensory and spiritual aspects. The Sacred Law has permitted a Muslim to choose any supplication that pleases him, as long as it does not involve aggression or severing ties of kinship, based on the Prophet's (PBUH) saying: "Then let each of you choose whatever supplication he likes best, and supplicate with it." Nevertheless, it is better for a Muslim to supplicate with the comprehensive, transmitted supplications found in the Qur'an and Sunnah.