"Faith in the Absent Imam"
The translation of verse 3 of Surah Al-Baqarah:
Who believe in the Unseen, are steadfast in prayer, and spend out of what We have provided for them.
Davood Raqee saying that Imam Sadiq said in the interpretation of this verse:
“Pious people are people who have faith in the uprising of Imam Mahdi (Qa’im) and admit it which is of course right.
Ithbat al-hudat, v. 5, p. 72