Musnad Ahmad 31:682

Hassan narrated to us, he said: I heard Abdullah ibn Lahi'ah, he said: Darraj Abu al-Samh narrated to us, that Abu al-Haytham narrated to him, from Abu Sa'id al-Khudri, from the Messenger of Allah, peace and blessings of Allah be upon him, that a man said to him: "O Messenger of Allah, blessed is he who saw you and believed in you." He said: "Blessed is he who saw me and believed in me, then blessed, then blessed, then blessed is he who believed in me and did not see me." A man said to him: "And what is Tuba?" He said: "A tree in Paradise, the distance of a hundred years, the garments of the people of Paradise come out from its calyxes."