Musnad Ahmad 97:0

Narrated to us by Yahya ibn Sa’id, from Hisham, who said: Narrated to us my father, from ‘Ubayd ibn Khalid al-Sulami, who said: The Messenger of Allah (ﷺ) established brotherhood between two men. One of them was killed in the path of Allah, and the other remained after him for a week—or he said: a month—then he died. The people mentioned the one who died after, and the Messenger of Allah (ﷺ) said: "What is it that you are finding strange?" They said: "O Messenger of Allah, this one was more diligent in his striving, then he died after him." The Messenger of Allah (ﷺ) said: "Did he not pray after him?" They said: "Yes." He said: "And did he not fast the month of Ramadan after him?" They said: "Yes." He said: "And did he not pray such-and-such number of prostrations in the year?" They said: "Yes." The Messenger of Allah (ﷺ) said: "The distance between them is greater than the distance between the heaven and the earth."