Tafsir of Al-Adiyat 100:4

(فَأَثَرْنَ بِهِ): Derived from al-itharah, which is the agitation and stirring up of dust and the like. The original form was athwarn (أثورن), but the vowel of the waw was transferred to the preceding letter, then the waw was changed into an alif, and subsequently deleted due to the meeting of two quiescent letters.

The verb is conjoined to the noun preceding it, which is al-'adiyat (the chargers), or to what follows it because it is an active participle (ism fa'il), which holds the meaning of a verb—especially when it occurs as a relative clause. It is as if it were said: "Those that ran, then struck fire, then raided, then stirred up." There is no anomaly in such a structure because the verb follows a noun; thus, it does not require the inclusion of al- (the definite article). There is no need to claim that it is conjoined to the implied verb that the active participle replaced.

The wisdom—as Ibn al-Munayyir stated—in bringing this as a verb after an active participle is to depict these actions in the soul. Depiction is achieved by introducing a verb after a noun due to the contrast between them, which is more eloquent than depicting them through uniform nouns. This is the same with the present tense following another present tense, as in the words of Ibn Ma'dikarib:

I have met the ghoul, plummeting With shooting stars like sheets of parchment, a vast expanse. So I seize it, and I strike it, and it falls Prostrate on its hands and its throat.

As for the benefit of this specific position, Al-Tibi stated that the horses were described with three attributes in order to predicate upon them what was intended regarding the attainment of victory. Therefore, this past tense verb and what follows it were brought forth as consequences of the active participles. This conveys that such constancy produced these two intended results. From this, it is understood that the particle fa (فَـ) is for tafri' (deriving/consequential inference), making what follows it a result of what preceded it. We will discuss this shortly, God Almighty willing.

The pronoun in bihi (به) refers to the dawn (subh), and the particle ba' (بـ) is adverbial—meaning they stirred up dust at that time. The specification of stirring it up at dawn is because it does not stir up, or its stirring does not become apparent, at night. By this, it becomes clear that the raiding which is not apparent during the day occurs at night. In the mention of stirring up dust, there is an indication—without explicit mention—of the intensity of the running and the frequency of the charges and retreats. They often refer to this with such expressions, among them the words of Ibn Rawahah:

May I lose my daughter if you do not see them Stirring up the dust from the sides of Kada'.

Abu Ubaydah said that naq' (نقع) means raising one's voice, citing the words of Labid: So when a truthful cry is raised, They milk it, full of noise and clamor. And the words of Umar (may God be pleased with him) when it was said to him on the day Khalid ibn al-Walid died that the women had gathered to weep for Khalid: "It matters not if the women of Banu al-Mughirah shed their tears for Abu Sulayman while sitting, so long as there is no naq' (loud wailing) or laqlaqah (shrieking)."

The meaning in that context is: they stirred up at that time a naq' (a cry), which is a shout of one who has surprised and struck the enemy. However, the first meaning is the more famous.

It is permissible that the pronoun in bihi refers to the running ('adw) indicated by al-'adiyat, or to the raiding (igharah) indicated by al-mughirat. The masculine gender is used by interpreting them as "running" (jari) or the like, and the ba' denotes causality or accompaniment; it is also possible for it to be adverbial, with the pronoun referring to the location indicated by the context. The first interpretation is more manifest and subtle.