that Rasoolullah صلي الله عليه و سلم mentioned the day of Friday and said:
"In it (the day of Friday) there is a time, if any Muslim servant finds it while he is praying and asking from Allah Ta'ala, Allah Ta'ala will grant him what he asked for."
And Rasoolullah صلي الله عليه و سلم indicated by his hand that it is a short period.