لَا بأْسَ طَهُورٌ إِنْ شَاءَ اللهُ

Never mind, may it (the sickness) be a purification, if Allāh wills.

Referência: Never mind, may it (the sickness) be a purification, if Allāh wills. Al-Bukhārī (#3616, 10/118).