Question:
When entering a mosque and the adhan (call to prayer) is being recited, is it permissible to perform wudu (ablution), pray sunnah, or go to the bathroom? What should one do?
Answer:
The basis for this question is the hadith: “When you hear the adhan, say as the mu’adhdhin says.” This means when the adhan is being recited, the listener is required to repeat the words. This is a command. So if you are about to engage in an activity that prevents you from responding to the adhan, that activity should not be done during the adhan.
If you are already praying sunnah when the adhan begins, you continue your prayer because you cannot interrupt it. But if you have not yet started, and the adhan begins, you should first respond to the adhan and then pray.
If you are performing wudu during the adhan, you can continue, because it does not prevent you from responding. You can say the adhan responses while washing your limbs. There is no prohibition.
If you need to use the bathroom, you must consider the urgency. If you cannot control yourself and need to go immediately, then go—because responding to the adhan is not obligatory to the point of harming yourself. But if you can wait until the adhan is over, it is better to wait, respond to the adhan, and then go. The reward for responding to the adhan is great, and you should not miss it without a valid reason.