What is the ruling on installing mihrabs in mosques?

The Shaykh : I had started a talk while we were leaving the Maghrib prayer with my brother Abu Lu'ay, who led us in the 'Asr prayer, and may Allah reward him well. I said to myself, while I was praying, "How fortunate this mosque is, whose imam prays this prayer." But as much as I rejoiced, I was grieved, because I knew that he is not the imam of the mosque. Is that correct?

The questioner : Yes.

The Shaykh : And upon you be peace, and the mercy of Allah and His blessings. I had intended in my heart, based on my assumption that he was the imam of the mosque, to remind him of an issue that many of our brothers, the people of the Sunnah, overlook. And although I learned that he is not the imam, I said that a reminder is necessary, because a reminder benefits the believers. And upon you be peace. As for him, first, he may return and lead prayer in the same mosque as an imam, just as he led the 'Asr prayer. And if he is not given the opportunity to pray in this mosque, he may pray in another mosque, similar to this one in that most mosques today are not free of mihrabs. The mihrab was not present in the time of the Messenger of Allah (peace and blessings be upon him), neither in his mosque, the Prophet's Mosque, nor in the other mosques scattered throughout Madinah. So the mihrab was not known in the early days of Islam in the mosques of the Muslims.