I was walking with the Prophet (s) in the lanes of Medina, when we ran into a tall, broad-shouldered, old man with a long beard. He greeted the Prophet (s) and expressed his respect. He then looked at me and said, ‘O the fourth of the vicegerents! Greetings, God’s Mercy and Blessings be upon you!’ He then looked at the Prophet (s) and said, ‘O Prophet of God! Is that not so?’ God’s Prophet (s) said, ‘Yes.’ Then he left. I asked God’s Prophet (s), ‘O Prophet of God! What is it that this old man said and you acknowledged?’ The Prophet (s) said, ‘You are what he referred to. Praise be to God. Indeed the Honorable the Exalted God has said the following in His Book, ‘I will create a vicegerent on earth…’ The vicegerent that God established on the Earth was Adam (s). God also said, ‘O David! We did indeed make thee a vicegerent on earth: so judge thou between men in truth (and justice)...’ Thus David was the second vicegerent. The Honorable the Exalted God said that Moses told his brother Aaron, ‘…Act for me amongst my people: Do right…’ It was Aaron who became the vicegerent of Moses (s) amongst the people. Thus Aaron was the third vicegerent. The Honorable the Exalted God said, ‘And an announcement from God and His Apostle, to the people (assembled) on the day of the Great Pilgrimage...’ It was you who announced this verse on behalf of God and His Messenger. You are my Trustee, my Vizier. You are the one to pay back my debts and to fulfill my promises. Your position relative to me is the same as that of Aaron’s position relative to Moses (s), with the only difference that there will be no Prophets after me. Thus you are the fourth vicegerent just as the old man who greeted you has said. Do you know who he was?’ I said, ‘No.’ The Prophet (s) said, ‘Know that he was your brother al-Khizr (s).’