Tafsir of Al-Muddathir 74:38

(Every soul, for what it has earned, is a pledge.)

It is held in pledge by Allah Almighty for its earnings. "Rahinah" (a pledge) is a verbal noun (masdar) in the sense of "rahn" (pledging/mortgage), similar to "shatimah" (abusing) in the sense of "shatm" (abuse); it is not an adjective. Were it an adjective, it would have been stated as "rahin," because the pattern fa'il in the sense of maf'ul (passive participle) does not take the feminine suffix (ta’), and it is uniform for both masculine and feminine.

An example of this is the saying of Abd al-Rahman ibn Zayd, whose father had been killed, and when seven blood-diets were offered to him, he refused to accept them:

"Is it after him who is in the mountain pass—the pass of Kuwaykib—"

"A pledge of a grave of soil and stones? Shall I remember [the need] for injustice against him who struck me down?"

"And my injustice is that I am a striver, not lagging."

The choice of "rahinah" (a pledge) over "rahin" (pledged), despite the latter’s balance with the oath and its lack of need for interpretation, is because the verbal noun here is more emphatic and thus more appropriate for the context. Therefore, one should not be distracted by the mere verbal parallel.

It has also been said that the ta’ in rahinah is for intensification. Abu Hayyan chose the view that it is a case where the nominal nature has dominated, like al-natihah (the gored animal), even if it is originally in the fa'il pattern in the sense of maf'ul. This is also a valid perspective, and he argued that the feminine usage in the poem is based on the meaning of "nafs" (soul).