""The invocation of any one of you is granted [by Allah] as long as he does not show impatience by saying "I have invoked Allah but my request has not been answered."
[Sahih al-Bukhari, Muslim]
"And when my servants ask you concerning me, [tell them] I am indeed near. I respond to the invocation of the supplicant when he calls."
[surah al Baqarah; 2:187]
