Jami` at-Tirmidhi 3310

Abu Hurairah said:“We were with the Messenger of Allah when Surat Al-Jumuah was revealed, so he recited it until he reached: And other among them who have not yet joined them, A man said to him: ‘O Messenger of Allah! Who are these people who have not yet joined us?’ But he did not say anything to him.” He said: “Salman [Al-Farsi] was among us.” He said: “So the Messenger of Allah placed his hand upon Salman and said: ‘By the One in whose Hand is my soul! If faith were on Pleiades then men among these people would reach it.”’