It was narrated to us by al-Shaykh, al-Faqih al-adūq (Abū Jaʿfar Moammed bin ʿAlī bin al-ussain bin Mūsa bin Bābawayh al-Qummi رحمه الله) who said – it was narrated to us by my father رحمه الله who said – it was narrated to us by ʿAbd Allāh bin al-assan al-Mu’adib, from Amed bin ʿAlī al-‘Abahāni, from Ibrāhīm bin Moammed al-Thaqafi, who said – it was narrated to us by Makhawal bin Ibrāhīm, who said – it was narrated to us by ʿAbd al-Ramān bin al-‘Aswad al-Yashkuri, from Moammed bin `Ubayd Allāh, from Salmān al-Fārsi رضي الله عنه, who said:

I asked The Messenger of Allāh صلى الله عليه وآله who is your successor from your nation (‘ummah), for a prophet is never sent except that he had a successor from his nation.
The Messenger of Allāh صلى الله عليه وآله said: “It has not been made clear to me yet.”
So I remained [alive] for as long as Allāh willed for me to remain, where therein I entered into the mosque, where The Messenger of Allāh صلى الله عليه وآله called me over and said: “Oh Salmān, you asked me about my successor from my nation, so do you know who was the successor of Mūsa in his nation?”
I said: “It was Yūshaʿ bin Nūn (Joshua), the youth (fatā).”
He said: “So do you know why he was made his successor?”
I said: “Allāh and His Messenger know best.”
He said: “He was made his successor because he was the most knowledgeable in his nation, after him. And my successor is the most knowledgeable in my nation after me, ʿAlī bin Abī Ṭālib.

حدثنا الشيخ الفقيه أبو جعفر محمد بن علي بن الحسين بن موسى بن بابويه القمي (رحمه الله)، قال: حدثنا أبي (رحمه الله)، قال: حدثنا عبد الله بن الحسن المؤدب، عن أحمد بن علي الأصبهاني، عن إبراهيم بن محمد الثقفي، قال: حدثنا مخول بن إبراهيم، قال: حدثنا عبد الرحمن بن الأسود اليشكري، عن محمد بن عبيد الله، عن سلمان الفارسي (رضي الله عنه)، قال: سألت رسول الله (صلى الله عليه وآله): من وصيك من أمتك، فإنه لم يبعث نبي إلا كان له وصي من أمته؟ فقال رسول الله (صلى الله عليه وآله): لم يبين لي بعد. فمكثت ما شاء الله أن أمكث، ثم دخلت المسجد، فناداني رسول الله (صلى الله عليه وآله) فقال: يا سلمان، سألتني عن وصيي من أمتي، فهل تدري من كان وصي موسى من أمته؟ فقلت: كان وصيه يوشع بن نون فتاه. قال: فهل تدري لم كان أوصى إليه؟ فقلت: الله ورسوله أعلم. قال: أوصى إليه لأنه كان أعلم أمته بعده، ووصيي أعلم أمتي من بعدي علي بن أبي طالب