The Holy Quran is a book of principles and guidelines.  The solution for every kind of problem is given in the Holy Quran in the form of principles and guidelines.  The scholars and the Imams extract and deduce a particular ruling from it in light of the principles.  Each and every issue has not been mentioned separately, but a thumb rule has been given in light of which the ruling of a particular issue can be deduced.  For e.g., the issue of bearing the expenses of the delivery of the wife, hospital charges, etc. has not been mentioned explicitly in the Holy Quran.  However the Holy Quran does say:

And treat them honorably.  Surah Nisa (4:19)

Similarly, the Holy Quran has mentioned the sacred teachings of the Holy Quran and His excellence at various places in the Holy Quran and has ordered us to describe the greatness and excellence of the Holy Prophet (Sallallahu alaihi wa sallam).  Through this basic principle, we have gotten the law that mention of the greatness of the Holy Prophet (Sallallahu alaihi wa sallam) should go on all the time.  On special days, it should be done with all the more fervor.

There is a verse of the Holy Quran:

O People of the Book! Indeed there has come to you Our Messenger who (clearly) unfolds to you many such things from the Book as you have been concealing and who overlooks many of (your) wrongs (too). There has indeed come to you a light from Allah (i.e., Muhammad [blessings and peace be upon him]) and an Enlightening Book (i.e., the Holy Quran).  Surah Maida (5:15)

He said that Almighty Allah has addressed the People of the Book

Almighty Allah has first mentioned the Mawlid of the Holy Prophet (Sallallahu alaihi wa sallam) and then the Seerah of the Holy Prophet (Sallallahu alaihi wa sallam) and has finished the verse with the mention of the Mawlid of the Holy Prophet (Sallallahu alaihi wa sallam).  Thus, Almighty Allah says at the end of this verse:

The manner and tone of the Holy Quran tells us that to understand the life of the Holy Prophet (Sallallahu alaihi wa sallam) and act upon it, the mention of the Mawlid of the Holy Prophet (Sallallahu alaihi wa sallam) is also very important.  To thank Almighty Allah for this great bounty, this is very important.

The glimpses of these teachings of the Holy Quran are seen in the life of the Companions as well.  In all the books of Hadith, one can find the mention of Mawlid of the Holy Prophet (Sallallahu alaihi wa sallam) and the excellence of the Holy Prophet (Sallallahu alaihi wa sallam).  If the Companions had not described the greatness and excellence of the Holy Prophet (Sallallahu alaihi wa sallam) in their gatherings, how would they be present in the canons of Hadith?

The Companions would make profuse mention of the Mawlid of the Holy Prophet (Sallallahu alaihi wa sallam) and His greatness.  No day would pass when the Holy Prophet (Sallallahu alaihi wa sallam) wouldn’t be mentioned.  They would mention Him each and every moment and each and every day of the year.  Would they have not described the greatness of the Holy Prophet (Sallallahu alaihi wa sallam) on the occasion of Mawlid itself?  Surely, their practices wouldn’t have changed.

Thus, in light of the Holy Quran and Hadith, to shake the Ummah from its slumber of heedlessness and to enthuse them, the scholars have declared this a commendable act.  Especially on the occasion ofMawlid, mention the Holy Prophet (Sallallahu alaihi wa sallam) and become aware of His teachings so that through its blessings, the remaining 11 months are also spent acting upon the Shariah