How sound is the saying: "Exalted are You, O Allah, and with Your praise; I bear witness that there is no god but You; I seek Your forgiveness and repent to You" after reciting the Qur’an?

The saying: "Glory be to You, O Allah, and with Your praise, I bear witness that there is no god but You, I seek Your forgiveness, and I repent to You," is prescribed after reciting the Qur'an outside of prayer, and after prayer. It is called "Kaffarat al-Majlis" (expiation for the assembly).