مسند أحمد

It was narrated that Ya'la bin Umayyah said:I said to 'Umar bin al Khattab رضي الله عنه , `And when you (Muslims) travel in the land, there is no sin on you if you shorten As­Salah (the prayer) if you fear that the disbelievers may put you in trial (attack you)` (al Nisa' 4:101]. But now the people are safe. He said: I wondered the same thing as you are wondering, and I asked the Messenger of Allah (ﷺ) ﷺ about that. He said: “It is a charity that Allah has bestowed upon you, so accept His charity.`