Here is an excerpt from Ibnul Qayyim (rahimahullaah):
There is an hour of acceptance, and it is the hour in which no Muslim happens to supplicate to Allah for something except that it will be given to him. In the hadeeth reported by al-Bukharee and Muslim on the authority of Abu Hurayrah that Allaah’s Messenger (salallaahu ‘alayhi wa sallam) said:
Indeed, there is an hour (opportune time) on Friday and if a Muslim gets it while praying and asks something from Allah, then Allah will definitely meet his demand. And he (salallaahu ‘alayhi wa sallam) pointed out the shortness of that time with his hands.
Translated by brother Salah al-Iranee