Al-Kāfi
Hadith 16022ـ عَنْهُ عَنْ يُونُسَ عَنْ بَعْضِ أَصْحَابِهِ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ قَالَ مُوسَى لِلْخَضِرِ (عَلَيهِ السَّلام) قَدْ تَحَرَّمْتُ بِصُحْبَتِكَ فَأَوْصِنِي قَالَ لَهُ الْزَمْ مَا لا يَضُرُّكَ مَعَهُ شَيْءٌ كَمَا لا يَنْفَعُكَ مَعَ غَيْرِهِ شَيْءٌ.
2. It is narrated from him (narrator of the Hadith above) from Yunus from certain individuals of his people from Abu ‘Abdillah (a.s.) who has said the following: “Moses said to Khidr, ‘I am honored to associate with you. Instruct me with good advice.’ Khidr said, ‘Hold fast to that with which nothing can harm you just as things without it will not benefit you.”’