Tafsir of Ghafir 40:51

(Indeed, We will surely support Our messengers and those who have believed...) This is a resumption of speech, initiated by Him (the Exalted) to explain that the punishment which befell the disbelievers—as previously narrated—is a branch of a universal rule necessitated by divine wisdom. It is that Our constant way is to support Our messengers and their followers (in the worldly life) with arguments, victory, and retribution against the disbelievers through extermination, combat, captivity, and other forms of punishment. It does not undermine this [rule] that the disbelievers may sometimes appear to have the upper hand as a trial, for the standard is determined by the consequences and the prevailing state of affairs. The full discussion regarding this has already been presented, so recall it.

(And the Day the witnesses stand)

(Meaning: The Day of Resurrection.) It is expressed in this manner to signal the nature of the support—that it will occur in the presence of the first and the last [generations], and that the witnesses will testify for the messengers regarding their conveying of the message, and against the disbelievers regarding their denial. Al-ashhad (the witnesses) is the plural of shahid (witness), similar to ashraf being the plural of sharif. It is also said: It is the plural of shahid based on the principle that the pattern fa’il may be pluralized as af’al. Some who do not permit that say: It is the plural of shahd (with a quiescent middle), which is a collective noun for shahid, just as they say dahb (with a quiescent middle) as a collective noun for sahib. Some have interpreted al-ashhad as the limbs [of the body], but that is not strong, as both [interpretations] derive from al-shahadah (testimony). It is also said: It is from al-mushahadah, meaning presence.

In the Khafaji annotations, it is stated that support in the Hereafter is never delayed, unlike in the worldly life, where war alternates between sides, even if the ultimate outcome belongs to the righteous. For this reason, the preposition fi (in) was used with "worldly life" rather than its counterpart, because the prepositional phrase majruur does not encompass [the scope of time] as the adverbial accusative does, as mentioned by the jurists of legal theory; however, there is room for debate in that view.

Ibn Hurmuz and Isma'il—and it is a narration from Abu 'Amr—read taqum (stand) with a feminine ta', signifying the group of witnesses.