Ibn ^Abbas Explains
Allah revealed in Surah Al-Qalam (S68), Ayah 42:
يَوْمَ يُكْشَفُ عَن سَاقٍ
It is very famously reported about Ibn ^Abbas, radiyAllahu ^anh, that Saq in this verse refers to “the severe afflictions of Judgement Day”.
The Apparent/Literal Meaning of Saq
The apparent meaning would be the organ composed of skin, muscle, bone, ligaments and marrow. If one took by this apparent meaning, adhered to it, and confirmed these organs then this is (clear-cut) kufr.
As for those who insist on it being a literal shin that is His Attribute, unsurprisingly, the famous word of an authority from the Salaf is meaningless to them. If a battle reached a very fierce point, it is said:
كشفت الحرب عن ساق
which means: “The battle exposed a saq.”
The Wahhabiyy Understanding of the Ayah
According to the Wahhabiyys this verse shows Allah has a shin. They say that Allah will expose and uncover His shin because to them it means “42. (Remember) the Day when the Shin shall be laid bare”. (So-Called “Translation of the meanings of the Noble Qur’an in the English Language” Page 777)
https://archive.org/details/EnglishTheHolyQuranTranslationByDarUsSalam/page/n789/mode/1up
Warning Against “So-Called Translations of the Quran”
Sahih International: The Day the shin will be uncovered and they are invited to prostration but the disbelievers will not be able,
Yusuf Ali: The Day that the shin shall be laid bare, and they shall be summoned to bow in adoration, but they shall not be able,-
Mohsin Khan: (Remember) the Day when the Shin shall be laid bare (i.e. the Day of Resurrection) and they shall be called to prostrate (to Allah), but they (hypocrites) shall not be able to do so,
Arberry: Upon the day when the leg shall be bared, and they shall be summoned to bow themselves, but they cannot;
Further Scans
Tafsir At-Tabariyy
Tafsir Al-Jalalayn
Tafsir Al-Baghawiyy
Al-Bahr Al-Muhit
Ibn Taymiyah’s Majmu^ Al-Fatawa
Al-Qamus Al-Muhit
Arabic-English Dictionaries
An Arabic-English Lexicon by Edward-William Lane
(Page 1471:) “… they mention the ساق when they mean to express the difficulty of a case or an event, and to tell of the terror occasioned thereby. (Ḳ, TA.) Thus, the saying يَوْمَ يُكْشَفُ عَنْ سَاقٍ, (Ṣ, Ḳ, TA,) in the Ḳur [lxviii. 42], (Ṣ, TA,) [lit. On a day when a shank shall be uncovered,] means † on a day when difficulty, or calamity, shall be disclosed. (I’Ab, Mujáhid, Ṣ, Ḳ, TA.) It is like the saying, قَامَتِ الحَرْبُ عَلَى سَاقٍ, (Ṣ, TA,) which means † The war, or battle, became vehement, (Mṣb in this art. and in art. حرب,) so that safety from destruction was difficult of attainment: (Id. in art. حرب: ) and كَشَفَتِ الحَرْبُ عَنْ سَاقٍ, [as also شَمَّرَتْ عَنْ سَاقِهَا,] i. e. † The war, or battle, became vehement. (Jel in lxviii. 42.)…”
http://lexicon.quranic-research.net/data/12_s/253_swq.html
Hans-Wehr 4th Edition
(Page 571: )