Q: What is the ruling on
the hadeeth which says that the Prophet used to place his right hand after
obligatory Salaah on his forehead and read this du’aa, “….”? 
A:
This
hadeeth is Da’eef (Weak).
It is narrated from two people
as Marfoo’:
1.     Anas bin Maalik (radiallah anhu) &
2.     Amr bin Qays (with a slight difference of wording) – and he is a
contemporary of Taabi’een but not a Taabi’ee.
 
