Some Proofs the Scholars gave for the Validity of the Mawlid?
The Prophet recognized Monday and praised fasting it, because he was born and received revelation on that day. He said:
ذاك يومُ أُنْزِلَ عليَّ ويومٌ ولِدتُ فيه
i.e., this is the day I was born. (Muslim)
Prophet Muhammad fasted the 10th of Muharram after he emigrated to Madinah. He found that the Jews commemorate every year the day Allah saved Prophet Moosa and his followers from Pharaoh. It was revealed to the Prophet what the Jews said was true, so the Prophet told them, as al-Bukhariyy narrated:
”نحنُ أَوْلى بموسى”
That is, “We are more deserving of Moosa than you” and the Prophet ordered the Muslims to fast the 9th and 10th of Muharram as optional days.