I am learning tajweed, while in the tajweed class couple of friends and I was in the discussion regarding who and when the Tajweed rules has been set. I will appreciate if anyone from this site tell me by whom and in what year Tajweed rules has been introduced.
Wa alaikum assalaam wa rahmatullahi wa barakatuh,
Masha' Allah, it is great to hear you are learning tajweed, and we ask Allah to make easy for you the learning and application of proper tajweed in the recitation of the Qur'an.
Please refer to the PDF download: http://www.abouttajweed.com/Why%20should%20we%20read%20the%20Quran%20tajweed.pdf
Tajweed rules were observed from the time of the Prophet, and were part of the revelation, but were written down 300 years later. The recitation of the Qur’an with tajweed then was from the Prophet . The need to write them down came with time as the Arabic tongue became corrupt and weakened by the entering of large numbers of non-Arabs into Islam.
The above PDF download gives more details and insha’ Allah answers your question.
You are welcome. Wa assalaam.