Our scholars said that he should not respond (1), because this adhan is not directed to him, and so he does not repeat it. They answered the hadith by saying that the customary practice in the Prophet’s time was for there to be only one caller to prayer, and it would not have been possible for another to give the adhan after the prayer had been performed. Thus, the hadith is to be understood according to what was customary in the Prophet’s time: the adhan was not repeated. Yet if someone were to apply the hadith in its general sense and say, “It is a form of remembrance, and since the hadith is general, there is nothing to prevent me from remembering Allah, Mighty and Majestic is He,” then there is no objection.
His statement, “It is recommended for the one who hears it to repeat it quietly,” clearly indicates that if he deliberately omits the response, he incurs no sin. This is the correct view. Some of the Zahiris held that repeating after the caller to prayer is obligatory, and that whoever hears him must say what he says (2).
They cited the command: “When you hear the caller to prayer, say what he says.” The basic principle concerning a command is that it denotes obligation, but the majority held otherwise (3).
The majority cited as evidence that the Prophet, peace and blessings be upon him, heard a caller to prayer giving the adhan and said, “Upon the natural disposition” (4). It has not been reported that he responded to him or repeated after him. Had repeating after the caller been obligatory, the Messenger, peace and blessings be upon him, would have done so, and it would have been transmitted to us.