Musnad Ahmad 26:115

Yahya narrated to us, from Shu'bah, who said: Abu Ishaq narrated to me, from Abu 'Ubaydah, from 'Abdullah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) passed by me while I was praying, and he said: "Ask, and you shall be given, O son of Umm 'Abd." Abu Bakr and 'Umar (may Allah be pleased with them both) hastened [to him]. 'Umar said: "Abu Bakr never hastened to anything before me, except that he preceded me to it." They asked him about what he had said, and he replied: "Among my supplications which I hardly ever omit is: 'O Allah, I ask You for a bliss that does not perish, and a coolness of the eye that does not end, and the companionship of the Prophet, Muhammad (peace and blessings of Allah be upon him), in the highest part of Paradise, the Garden of Eternity.'"