Muhammad b. al-Hasan b. Ahmad b. al-Walid (ra) narrated to us. He said: Ahmad b. Idris narrated to us. He said: Muhammad b. Ahmad b. yahya b. `Imran al-Ash`ari narrated to us from Ibrahim b. Ishaq al-Nahawandi from Muhammad b. Sulayman al-Daylami from his father. He said
I heard Aba `Abdillah al-Sadiq (as) say: Winter is the springtime of the believer – night is prolonged in it, which helps him stand up in prayer in it; and its day is shortened, which helps him fast in it.