Musnad Abi Ya'la 181 — he said: I asked Sayyiduna Umar: Why are people

It is narrated from Sayyiduna Ya'la bin Umayyah (may Allah be pleased with him) that he said: I asked Sayyiduna Umar (may Allah be pleased with him): "Why are people shortening the prayer nowadays (even in a state of security), when the saying of Allah, Glorified and Exalted, is: 'If you fear that those who disbelieve may put you to trial,' and that time (of fear) has now passed (and there is security everywhere)?" At this Sayyiduna Umar (may Allah be pleased with him) said: "I too was surprised at the very thing that has surprised you, so I asked the Messenger of Allah (peace and blessings be upon him) about it, and he (peace and blessings be upon him) said: 'It is a charity which Allah Almighty has bestowed upon you, so accept His charity (gladly).'"