1-This is the literal translation of the Qur'anic phrase used here. The exegetes have explained it in two different ways. Some of them are of the view that, according to the Arabic usage, 'exposure of the shin' is an idiomatic expression for a severe state of distress. When a person is confronted with such a distress, he normally lays his shins bare. Therefore, exposure of the shin has been taken as indicative of such a state. Given this interpretation, the verse means that on the day when the disbelievers will face the severe distress, they will be called upon to prostrate themselves, but they will not be able to do so, because their backs will be made flat, with no elasticity to bow down. Some other commentators, however, take the phrase in its literal sense. They say that the 'Shin' referred to here is the Shin of Allah Ta'ala, which is one of His attributes, the exact nature of which is neither known to anybody, nor discoverable in this world. (But obviously, it is not like the shins of human beings). According to this interpretation, the verse means that, at some stage on the Day of Judgment, Allah Ta'ala will expose this attribute of His which is called 'Shin', and they will be called upon to prostrate before it. This interpretation is supported by an authentic hadith reported by Bukhari and Muslim.

2-It refers to Sayyidna Yunus (علیہ السلام) who was devoured by a fish after he left his nation. Full description of the event has been given in Surah Yunus. (Muhammad Taqi Usmani)

3-According to the explanation given to this verse by Maulana Ashraf Ali Thanawi (رح) ، 'Favour from His Lord' means the acceptance of his repentance, and 'wilderness' refers to the place where he was thrown by the fish. If this verse is read in juxtaposition with Verses 143, 144 of Surah As-Saffat, the sense appears to be that if Yunus had not offered tasbih and taubah, he would have remained in the belly of the fish for good, and if he had repented, but was not favoured by Allah with the acceptance of his taubah, he would have been cast by the fish into the wilderness, due to his repentance, but in a reproachable state. However, since Allah favoured him with accepting his taubah, he was no more reproachable. Some other scholars, however, suggest that 'wilderness' in this verse refers to the plain of Hashr, and the verse means that if Allah had not accepted his taubah, he would have been cast into the plain of Hashr in a reproachable state.

4-It means that they glare at you with such a hatred and anger as if they were to make you slip from your standpoint due to their aversion.