Al-Kāfi - Volume 3 > Where to Apply Rules about Salah (Prayer) on a Journey
Hadith #1

1ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ مُحَمَّدِ بْنِ الْحُسَيْنِ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنِ الْعَلاَءِ بْنِ رَزِينٍ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ قَالَ قُلْتُ لأَبِي عَبْدِ الله (عَلَيْهِ الْسَّلام) الرَّجُلُ يُرِيدُ السَّفَرَ مَتَى يُقَصِّرُ قَالَ إِذَا تَوَارَى مِنَ الْبُيُوتِ قَالَ قُلْتُ الرَّجُلُ يُرِيدُ السَّفَرَ فَيَخْرُجُ حِينَ تَزُولُ الشَّمْسُ قَالَ إِذَا خَرَجْتَ فَصَلِّ رَكْعَتَيْنِ. وَرَوَى الْحُسَيْنُ بْنُ سَعِيدٍ عَنْ صَفْوَانَ وَفَضَالَةَ عَنِ الْعَلاَءِ مِثْلَهُ.

1. Muhammad ibn Yahya has narrated from Muhammad ibn al-Husayn, from Safwan ibn Yahya from al-‘Ala’ ibn Razin from Muhammad ibn Muslim who has said the following: “I once asked abu ’Abd Allah, ‘Alayhi al-Salam, about a man who wants to travel. Where is he required to apply the rules about journey? He (the Imam) said, ‘He must apply them where houses become invisible to him? I then asked, ‘A man begins his journey on Zawal (declining of the sun toward the west at noontime). What is he required to do? 5 He (the Imam) said, ‘When you come out perform two Rak‘at Salah prayers).’ Also al-Husayn ibn Sa‘id has narrated from, Safwan and Fadalah from al-‘Ala’ a similar Hadith.”