Firstly, we don't actually know when is his birthday.
Secondly, no injunctions to do so either in Quran nor hadiths.
Thirdly, his companions never did. Only started celebrating it by people who did not know him and to emulate how christians celebrate Jesus' birthday.
Forthly, If really want to celebrate his birthday, then fast on every Mondays. That's what he used to do.
The Prophet (saw) was asked about the voluntary fasting on Mondays, and he replied saying, “On that day I was born, and on it the Revelation came to me.”
Fifthly, if you take the celebration as part of worship or ibadah, then it all becomes bidaah or innovation in the religion. Then there will be no end to innovation in religion, becoming like the christians.
Sixthly, if you really want to have remembrance of his birthday, what better way than to follow the Quran and hadiths strictly as what he taught us and leave making new things up.
Firstly, we do know his birthday depending on what sect "we" (i.e. you) belong to.
Secondly, nowhere is there any injunction on doing so, nor is there any prohibition on doing so.
Thirdly, his companions never did many things like using the internet or mobile phones or other modern tech, doesn't mean anything regarding today's or future generation's abilities or choices. BTW Christians don't know when Prophet Isa (PBUH) was born, so they have separate christian calendars like gregorian, julian, eastern orthodogx and so on. they celebrate new year on jan 1, but say Prophet Isa (PBUH) was born on either 25 Dec or Jan 7, although their calendar is supposed to start from hsi day of birth.
Fourthly, celebrating his birthday and fasting on
every Mondays has no relationship whatsoever. Btw, what is the source of this saying that you quoted:
"The Prophet (saw) was asked about the voluntary fasting on Mondays, and he replied saying, “On that day I was born, and on it the Revelation came to me.”
We should remember that Hadiths were compiled about 200 years afterwards, and a hadith in "sahih" Bukhari urges followers to drink camel urine. I hope for your own sake that you have not started drinking camel urine.
Fifthly, nobody should take celebrating his birthday as worship or ibadah. That would be absurd and indeed a "bidah" or innovation in religion. There is no room for such bidah or "innovation in religion".
Sixthly, he left nothing "strictly" speaking since the Quran was from Allah (SWT) and impossible to alter, modify, corrupt even if the entire planet incl those unborn souls were to work together as promised by Allah (SWT) in the Quran itself, while for Hadiths, they are not
remotely comparable since they were compiled 200 years afterwards and every single error, contradiction and "problem" can be traced back to Hadiths (incl that hadith on camel urine drinking).
This is precisely why you have different versions of Hadiths for different "sects", so how exactly can you or anyone else say nonchalantly just follow Quran and Hadiths without making things up when clearly at least some/most Hadiths were made up and recognized by all so called scholars themselves as such. Otherwise there would not be different sects within Islam with different sets of Hadiths and different self proclaimed scholars, who are not appointed by Allah (SWT) by the way, claiming that such and such Hadiths are weak and such and such Hadiths are authenetic.
Moreover, how can we reconcile the idea of Hadiths that were compiled 200 years afterwards with the idea that during these 200 years with no compiled set of Hadiths around, were there no believers, no Muslims anywhere in the world? Are the Hadith fanatics now suggesting that upto the day Bukhari or other compilers completed compiling the Hadiths, no other Muslim had ever lived or existed on Earth?
Difficult questions to answer for Hadith fanatics.
We must also be wary of putting suudi bedouing low IQ negroes on a pedestal since negroes, by default, are low IQ cretins closer to animals than human beings and are totally incapable of developing a single highly advanced civilization. That is precisely why the simple reason yankees have been the dominant power specially since 1991 Soviet collapse has been Suudi backing yankees with their petrodollars, despite Yankees being openly kafir, anti Islamic, anti Muslim. Suudis simply haven't got the brains to outwit the Yankees, the reason being suudis are negroes.
It's not like historically they were superior. They were ruled by Turks for some 400 years to 600 years too. They even admit to 500 years of Western domination, rather than 200 years of Western domination, proving they were genetically inferior. Doesn't matter why, if you or your ilk were dominated for a single nanosecond longer than the period from onset of industrial revolution to current era, than you were genetically inferior. Period.
So egyptians and suudis were proven to be genetically inferior. Since they have admitted that they were dominated by West for 400 or 500 years now. Actually those races were dominated for much longer. E.g. anatolia, iran, egypt, syria, libya, iraq, tunisia, etc were all ruled/conquered/dominated by greeks, romans and/or mongols but NONE of them could ever go and conquer Rome in return in last 2000 years, nor could they go and conquer Mongolia in last 700 years, proving their genetic inferiority.
We should be wary of putting genetically inferior negroes on a pedestal. If they can't even defeat or crush or dominate the West/Europe in the last 2000 years (e.g. in last 2000 years, NONE of them could conquer Rome once while the reverse is not true), then they are genetically inferior.
Btw, just to set the records straight, as late as 18th century of christian era, AFTER Industrial revolution, pommies were STILL defeated by Bangla Subah in Battle of Coalcutta
Only at battle of Plassey were the pommies able to defeat Bangla Subah thanks to treachery and backstabbing. A trait that brits are infamous for and a trait that brits have frequently used, abused aplenty.
Otherwise, long before Industrial Revolution, teeny tiny Bangla subah ALONE had a larger economy than ALL of Western europe combined. Truth might hurt, but ASEAN got no such history or heritage or legend or scholar or civilization or ability or talent.
And sadly, neither do the negroes.
When we say this century will be Asian Century, certainly middle east with its teeny tiny joke sized population won't count, and with its PATHETIC history of last 2000 years of failure after FAILURE to capture Rome or failure to capture Mongolia (in last 700 years), they stand no chance.
History doesn't favour them simpel as that, which is why you see or hear egyptian negroes say they were dominated by West for last 400 years or suuudis say that the west dominated them for last 500 years.
Even the Industrial Revolution was preceded by a period of "proto industrialization" a phase
already attained by Bangla Subah before the kafir devilish pommmie thieves made their way to Bangla Sultanate or Bangla Subah or Mughal Sultanate.