Please, what do mean by Hafs?
Wa alaikum assalaam wa rahmatullahi wa barakatuh,
There are different authentic ways of reading the Qur’an. The most prevalent in this day and age is the way of Hafs ‘an ‘Aasim. Hafs is the name of a man and so is ‘Aasim. Hafs read the Qur’an and took the ways taught to him by his sheikh ‘Aasim. There were of the early scholars of recitation and although the way of reading of Hafs ‘an ‘Aasim has authentic chains back to the Prophet, it became popularly known as Hafs ‘an ‘Aasim. Some Muslims further abbreviate it to Hafs, but it always best to include "‘an ‘Aasim" (from ‘Aasim) to make clear the way of recitation being referring to.
Please also see:
http://www.abouttajweed.com/30120202.htm (number 5) .