Sahih Bukhari Volume 1, Book 10, Hadith 654

‏"‏ وَلَوْ يَعْلَمُونَ مَا فِي التَّهْجِيرِ لاَسْتَبَقُوا إِلَيْهِ، وَلَوْ يَعْلَمُونَ مَا فِي الْعَتَمَةِ وَالصُّبْحِ لأَتَوْهُمَا وَلَوْ حَبْوًا ‏"

and if they knew the reward of offering the Zuhr prayer early (in its stated time), they would race for it and they knew the reward for 'Isha and Fajr prayers in congregation, they would attend them even if they were to crawl.")