Why do the Egyptian Dar al-Ifta and Al-Azhar permit celebrating the Prophet's Birthday despite it being an innovation (bid'ah), and how do we respond to those who argue for its permissibility based on its authorization by these two institutions?

Celebrating the Mawlid is an innovation (bid'ah) for which there is no evidence. It was not practiced during the era of the Rightly Guided Caliphs, nor by the Companions, nor by the Successors. None of the imams of the four madhhabs advocated it. If it were good, they would have preceded us in it. In fact, the first to practice it were the Ubaydi Fatimids, in imitation of the Christians who celebrated the birth of Jesus. Therefore, it must be abandoned because it is an innovation and an imitation of Christians in what they innovated. The Islamic law has appointed two Eids for us, and we must restrict ourselves to them. Regarding the disagreement among later scholars between it being an innovation and permissible, the prohibitor takes precedence over the one who permits, and the Rightly Guided Caliphs did not practice it. Those who deemed it good, did so for worship, reading the Sira (Prophet's biography), and reciting eulogies, not for singing and the immorality of the people of falsehood.