Those among them who have not yet joined them

Hazrat Abu Hurairah, may Allah be pleased with him, narrates:

“We were sitting with the Holy Prophet, peace and blessings of Allah be upon him, when Surah al-Jumuah was revealed to him. When he recited the verse, ‘And among others from among them who have not yet joined them’, a man asked, ‘O Messenger of Allah, who are these people (who will hold the rank of the companions of the Prophet and have not yet joined them).’ But the Prophet^sa did not answer him. The man repeated his question three times. The narrator says that Hazrat Salman Farsi^ra was sitting amongst us. The Holy Prophet^sa put his hand on his shoulder and said, ‘Even if faith was to ascend to the Pleiades, men from among his people will bring it back to earth.’”

(Sahih al-Bukhari)