I said, "O Allâh's Messenger (ﷺ)! Which mosque was first built on the surface of the earth?" He said, "Al-Masjid-ul-Harâm (at Makka). I said, "Which was built next?" He replied, "Al-Masjid-ul-Aqsa (at Jerusalem)." I said, "What was the period of construction between the two?" He said, "Forty years." He added, "Wherever (you may be, and) the Salât (prayer) time becomes due, perform the (prayer) there, for the best thing is to do so [i.e. to offer the (prayers) in time]. [4:585-O.B]