al-Ṣādiqīn is interpreted in three ways:
1. By al-Ṣādiqīn, the prophets (anbiyāʾ) are meant, as in the following verses:
So that He may question the ṣādiqīn (that is, the prophets) about their truthfulness (that is, whether they conveyed the message they received from Allah to their people). (al-Aḥzāb 33:8)
This is the Day when the truthfulness of the ṣādiqīn (that is, the prophets) will benefit them. (al-Māʾida 5:119)
2. The term al-Ṣādiqīn specifically describes the Emigrants (muhājirūn), as in the following verse:
(The spoils of war which Allah has given to His Messenger) are for the poor Emigrants who were expelled from their homes and their properties, seeking bounty from Allah and [His] approval, and supporting Allah and His Messenger. Those are the ṣādiqūn. (al-Ḥashr 59:8)
3. The term al-Ṣādiqīn describes the believers (muʾminūn), as in the following verse:
So that Allah may reward the ṣādiqīn (that is, the believers) for their truthfulness... (al-Aḥzāb 33:24)