COMMENTARY on 17:7
A. Yusuf Ali:

Translation:
If you did well, you did well for yourselves; if you did evil, (you did it) against yourselves. 2177 So when the second of the warnings came to pass, (We permitted your enemies) to disfigure your faces, 2178 and to enter your Temple 2179 as they had entered it before, and to visit with destruction all that fell into their power. 2180
Commentary:

2177  This is a parenthetical sentence. If anyone follows Allah's Law, the benefit goes to himself: he does not bestow a favour on anyone else. Similarly evil brings its own recompense on the doer of evil.

2178  The second doom was due to the rejection of the Message of Jesus. "To disfigure your faces" means to destroy any credit or power you may have got: the face shows the personality of the man.

2179  Titus's destruction of Jerusalem in 70 A.C.. was complete. He was a son of the Roman Emperor Vespasian, and at the date of the destruction of Jerusalem , had the title of Caesar as heir to the throne. He ruled as Roman Emperor from 79 to 81 A.C..

2180  Merivale in his Ramans Under the Empire gives a graphic account of the siege and final destruction (ed. 1890, 7:221-255). The population of Jerusalem was then 200,000. According to the Latin historian Tacitus it was as much as 600,000. There was a famine and there were massacres. There was much fanaticism. The judgement of Merivale is: "They" (the Jews) "were judicially abandoned to their own passions and the punishment which naturally awaited them." (7:221).

 

Muhammad Asad:

Translation:
[And We said:] "If you persevere in doing good, you will but be doing good to yourselves; and if you do evil, it will be [done] to yourselves." And so, when the prediction of the second [period of your iniquity] came true, [We raised new enemies against you, and allowed them] to disgrace you utterly, 9 and to enter the Temple as [their forerunners] had entered it once before, and to destroy with utter destruction all that they had conquered.
Commentary:
9  Lit., "to bring evil to your faces". Inasmuch as the face is the most prominent and expressive part of the human body, it is often used as a metonym for one's whole being; hence, the "evil done to one's face" is synonymous with "utter disgrace". Most probably, this passage relates to the destruction of the Second Temple and of Jewish statehood by Titus in the year 70 of the Christian era.