Ayesha and Ibn Abbas have narrated that the Messenger of Allah (ص) said:
"Remembrance of Ali (ع) is worship"
Manawi says: It means worship of God and God rewards one for this act.
Dailami, Ferdaus al-Akhbar, V. 2, page 244, V.3151; Suyuti, Al-Jami' as-Saghir, V.1, page 665; Muttaki Hindi, Kanz al-Ummal, V. 11, page 601; Ibn Maghazli, Manaqib Ali ibn Abi Talib, page 172; Ibn Asaker in Tarikh Madinah-Damishq, V.42, page 356; Ibn Marduyeh Esfahani, Manaqib, page 75