Sahih al-Bukhari 5294
Narrated Abu Huraira:
Abul Qasim (the Prophet (ﷺ) ) said, "There is an hour (or a moment) of 
     particular significance on Friday. If it happens that a Muslim is 
     offering a prayer and invoking Allah for some good at that very 
     moment, Allah will grant him his request." (The sub-narrator placed 
     the top of his finger on the palm of the other hand between the middle
     finger and the little one.)
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا بِشْرُ بْنُ الْمُفَضَّلِ، حَدَّثَنَا سَلَمَةُ بْنُ عَلْقَمَةَ، عَنْ مُحَمَّدِ بْنِ سِيرِينَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ أَبُو الْقَاسِمِ صلى الله عليه وسلم ‏
"‏ فِي الْجُمُعَةِ سَاعَةٌ لاَ يُوَافِقُهَا مُسْلِمٌ قَائِمٌ يُصَلِّي، فَسَأَلَ اللَّهَ خَيْرًا، إِلاَّ أَعْطَاهُ ‏"‏‏.‏ وَقَالَ بِيَدِهِ، وَوَضَعَ أَنْمَلَتَهُ عَلَى بَطْنِ الْوُسْطَى وَالْخِنْصَرِ‏.‏ قُلْنَا يُزَهِّدُهَا‏.‏