Hadith 4:22
Abu Musa reported God’s messenger as saying, “When a man is ill or on a journey, what he was accustomed to do when staying at home and well will be recorded for him.”(This refers to his observance of salat , etc., cf. the traditions of ‘Abdallah b. 'Amr and Anas on p. 326.) Bukhari transmitted it.
وَعَنْ أَبِي مُوسَى قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا مَرِضَ الْعَبْدُ أَوْ سَافَرَ كُتِبَ لَهُ بِمِثْلِ مَا كَانَ يعْمل مُقيما صَحِيحا» رَوَاهُ البُخَارِيّ
Original Reference: Mishkat al-Masabih 1544