Holding the Mus-haf for one who is following an imaam is contrary to the Sunnah

Holding
the Mus-haf for this reason is contrary to the Sunnah, for several reasons: 

1.It prevents a person from
placing his right hand over his left when standing.

2.It leads to a lot of unnecessary
movements, such as opening the Mus-haf, closing it, and placing it under
one’s arm.

3.These movements are very
distracting to the worshipper.

4.It prevents the worshipper
from looking at the place of sujood. Many scholars say that looking
at the place of sujood is Sunnah and is better.

5.The one who does that may
forget that he is in prayer, unless his heart is properly focused upon
his being in prayer, unlike when he is standing in a humble and focused
manner with his right hand upon his left, tilting his head towards the
place of sujood. In this case he will be more likely to remember that
he is praying and that he is behind the imaam.