Abdur Rahman bin Hajjaj says:
I was between Mecca and Medina alone in the company of
Imam Ja’far Sadiq (a.s.) and I asked: “What is the sign of the
Imam?”
He (a.s.) replied: “If he asks this mountain to come, it would
obey.”
Abdur Rahman says: “By God, I saw the mountain
approach.
Behaarul Anwaar, vol. 47, p. 101
Isbaatul Wilayah (Part One) – Ayatullah AliNamazi Shahroodi (r.a.)