From Sahih Bukhari (Hadith 3425):
Narrated Abu Dharr:I said, "O Allah's Messenger (ﷺ)! Which mosque was built first?" He replied, "Al-Masjid-ul-Haram." I asked, "Which (was built) next?" He replied, "Al-Masjid-ul-Aqsa (i.e. Jerusalem)." I asked, "What was the period in between them?" He replied, "Forty (years)." He then added, "Wherever the time for the prayer comes upon you, perform the prayer, for all the earth is a place of worshipping for you
Reference: Bukhari 3425