Heraclius, the Emperor, took out pictures from a golden chest and showed them to Hishaam radhialalhu anhu. The first showed a person with large eyes, sizeable pelvic area and long neck. He had no beard, wore two locks of hair and was one of the best looking people ever created. The Emperor said this was Aadam alaihis salaam. The next was a man with curly hair, reddish eyes, a large forehead and a striking beard. He said it was Nooh alaihis salaam. The next picture was of an extremely fair man with beautiful eyes, a conspicuous forehead, long cheeks and a white beard. He said it was Ibrahim alaihis salaam.
The next picture Hishaam recognized as the Prophet sallallahu alaihi wa sallam, who had passed away. The next showed a very tanned man, dark in complexion, with very curly hair and deep, penetrating eyes. He said it was Moosa alaihis salaam. Next to this was a picture resembling Moosa alaihis salaam except that this man’s hair was oiled, his forehead wide and his eyes slightly squint. He said this was Haroon alaihis salaam.
The next was a tanned man of average height and straight hair. He said it was Loot alaihis salaam.
The next was a fair man with reddish complexion, high-bridged nose, thin cheeks and handsome face. He said it was Is’haaq alaihis salaam. The next looked like Is’haaq alaihis salaam except he had a mole on his lip. He said this was Ya’qoob alaihis salaam. The next showed a fair person with a high-bridged nose, handsome face which shone with radiance and humility and had a tinge of reddishness. He had perfect build. He said this was Ismail alaihis salaam. The next showed a man who resembled Aadam alaihis salaam and whose face appeared to be the sun itself. He said it was Yusuf alaihis salaam.
The next picture showed a man with thin calves, small eyes, a large belly, of average height and reddish complexion. He said this was Dawood alaihis salaam. The following picture showed a man with long legs and a large pelvic area. He was riding a horse. He said this was Sulaiman alaihis salaam. The final picture was of a youthful person with a pitch black beard, lot of hair, striking eyes and a handsome face. He said this was Isa alaihis salaam.
Hishaam asked Heraclius where he’d got the pictures from. He replied that they were given to Aadam alaihis salaam when he asked Allah to show him the Prophets from his progeny. They lay in the treasures of Aadam alaihis salaam at the place where the sun sets. Zul Qarnayn took them from there and gave them to Prophet Daaniyaal alaihis salaam.
Hishaam narrated this incident to Abu Bakr radhiallahu anhu who said the Prophet sallallahu alaihi wa sallam informed the Sahaba that Christians (like Heraclius) and Jews have the description of Muhammad sallallahu alaihi wa sallam with them.
This story is narrated in Hayatus Sahabah (vol 3, pg 561-3) which quotes it from Haakim as quoted in Tafsir Ibn Kathir (vol 2, pg 251). Kanzul Ummal (vol 5, pg 322) reports it from Baihaqi and quotes from Ibn Kathir that the chain of narrators is sound. Similar narration in Dalaail pg 9.