وَصَدَّقَ بِالحُسنىٰ

And confirms the best promise.

EXEGESIS

The word ḥusnā is the feminine form of aḥsan. It is plausible that grammatically, ḥusnā is an adjective for an omitted noun such as ‘promise’. The best promise could be a reference to the promise Allah has made about the abundant rewards He has prepared for those who spend in His way.^{‎[1]Munyah, 30/405; Mizan, 30/303.} It can also refer to the ultimate reward which is paradise.

Ṣaddaqa means to confirm the promise by having faith in its truth. In this context it refers to those who give charity whilst having faith in the reward of Allah that awaits them in the hereafter.^{‎[2]Amthal, 20/256.} This meaning of ḥusnā seems to have also been used in 4:95.

INSIGHTS FROM HADITH

1. It has been reported from Imam al-Ṣādiq (a) that ḥusnā refers to wilāyah (divine guardianship of the Imams).^{‎[3]Furat, 1/568; Qummi 2/426.}

Note: This would be an application of the verse.

REVIEW OF TAFSĪR LITERATURE

Regarding what ḥusnā is a reference to, it has been said that it is a reference to belief in the oneness of Allah (tawḥīd) and belief in Allah.^{‎[4]Tibyan, 10/363.} Others say it is a reference to the hereafter,^{‎[5]Al-Balāgh fī Tafsīr al-Qurʾān bil-Qurʾān, 1/595.} paradise,^{‎[6]Tabrisi, 10/760; Tibyan, 10/363.} or belief in prophethood.^{‎[7]Mudarrisi, 18/151.}

[1] Munyah, 30/405; Mizan, 30/303.
[2] Amthal, 20/256.
[3] Furat, 1/568; Qummi 2/426.
[4] Tibyan, 10/363.
[5] Al-Balāgh fī Tafsīr al-Qurʾān bil-Qurʾān, 1/595.
[6] Tabrisi, 10/760; Tibyan, 10/363.
[7] Mudarrisi, 18/151.