In the Name of Allah, the Merciful, the Compassionate
Praise be to Allah for His bounties, and peace be upon Muhammad and his family. This is the emendation of A Shi‘ite Creed of Abu Ja‘far Ibn Babawayh, may Allah have mercy upon him, compiled by ash-Shaykh al-Mufid Abu ‘Abdillah Muhammad ibn an-Nu‘man*, may Allah have mercy upon him.
On a day when a shank (saq) shall be bared, and they shall be summoned to prostrate themselves, but they cannot [68:42].
as-Saq (shank) here means the result, or consummation of the affair and its intensity.
Ash-Shaykh al-Mufid says: The meaning of the verse quoted above is intended for the Day of Resurrection on which an important, hard and intense matter will be disclosed, and that will be the reckoning and scrutinizing of (man's) actions; the recompensing for (good or bad) deeds, and the divulging of the heart secrets; the revealing of mysteries, and the appraisal of good and bad acts. Hence, He (Allah) designates by as saq the gravity of the matter; and by the same reasoning, the Arabs used to symbolize the violence and severity of war with their peculiar expression, "The war broke out [amongst us] (qamati 'l-harbu [bina] ‘ala saq)"3 .
And their poet, Sa‘d ibn Khalid, says:
The war disclosed all its severety, and revealed its full calamity.
The eagle of death appeared,
Bearing in its train the decreed fate.
Also, like this is their expression, "The fair is set up", (qad qamati 's-suq), denoting when the people crowd together, and buying and selling goes briskly with much effort and exertion.