What is the ruling on repeating the adhan?

Question:
May Allah reward you, Honorable Shaykh. This questioner says: What is the ruling on following the mu'adhdhin? And if it is not obligatory, what is the reason it is not obligatory?

Answer:
Repeating means following the mu'adhdhin; his intention is following the mu'adhdhin. It is called repeating, or rather following. In this there is the reward that the Prophet (peace and blessings be upon him) informed us of: that whoever hears the mu'adhdhin and says what he says, then says, "O Allah, grant this call a good response, and a prayer that is accepted, grant Muhammad the intercession and the excellence, and complete for him the honored position that You promised," and he prays upon the Prophet (peace and blessings be upon him) before this supplication. When he says "La ilaha illa Allah," he says, "O Allah, send blessings and peace upon Muhammad. O Allah, our Lord, grant the reward of the desire." The Messenger (peace and blessings be upon him) said: .
This is a great virtue, and it is not obligatory. It is among the virtues of deeds, so if one leaves it, he owes nothing.
The Messenger did not command this matter; rather, he said, "Whoever does such and such, he will have such and such." So he did not command, saying, "Say what the mu'adhdhin says," as the questioner imagined. Rather, the Messenger said, "Whoever hears the mu'adhdhin and says what he says, and so on."