Answer
Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
The origins of Islamic Prayer are the divine inspiration given to the Prophet (peace be upon him). So, it is absurd and ridiculous for anyone to make such an allegation that the Prophet copied the Islamic Prayer from Judaism and Zoroastrianism.
Responding to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
The origins of Islamic Prayer are the divine inspiration given to the Prophet (peace be upon him). The Prophet (peace be upon him) was an ummi or untutored and never attended any school or learned from any human being.
Allah says: “You recited no Scripture before We revealed this one to you; you never wrote one down with your hand. If you had done so, those who follow falsehood might have had cause to doubt.” (Al-`Ankabut 29:48)
Most of the converts that came to Islam from Judaism, Christianity, and Zoroastrianism; all three religions were accorded the status of the People of the Book; they were free to practice their religion. And even Western historians who studied conversions to Islam have concluded that conversions to Islam were gradual and peaceful.
When we look at the prayers of these religions and compare them with that of Islam, we will see the unique nature of Islamic Prayer.
First, the postures of Islamic Prayer involve standing, bowing and prostrating, and sitting. It does not incorporate any pagan rituals of images or fire.
The call to Prayer in Islam is also unique; those who listen to it have expressed its beauty and the highly impactful spiritual experience; it has even driven several people to embrace Islam.
Granted that the Prophet Muhammad copied this from the Jews and Zoroastrians, the enemies of the Prophet who were eager to use any loophole to attack Islam would have used it as the perfect weapon.
Also, it would have stopped the Jewish rabbis and practitioners of these religions from embracing Islam. Instead, we have several of them in Madinah who hastened to embrace Islam in Madinah. Some even went as far as writing off their entire property to the cause of Islam before achieving martyrdom.
So, it is absurd and ridiculous for anyone to make such an allegation that the Prophet (peace be upon him) copied the Islamic Prayer from Judaism and Zoroastrianism.
Finally, let me cite the tradition that directly answers your question as to who taught the Prophet (peace be upon him) how to pray:
Zayd ibn Harithah, one of the earliest converts to Islam (who was the adopted son of the Prophet before Allah abolished adoption), states that the angel Jibreel came to the Prophet early on in the first phase of his call to prophethood and taught him how to perform ablution and Prayer.” (Ahmad)
Ibn Abbas narrates the Prophet’s statement: Jibreel led me in Prayer twice near the House.” He goes on to mention how he led him in two consecutive days leading in each of the five daily prayers on their appointed times: the first day in the beginning and the next day at the end of the time.” (At-Tirmidhi, Abu Dawud, and others)
Almighty Allah knows best.
Source: AsktheScholar.Com