Thank you for that explanation of how future/past tenses are used in the Quran.Hi Sunrise . Your concern is right . To know Qur'an properly you have to have a strong sense of Arabic language . Please see below concerning the right meaning of 17:104 :
Almighty GOD has used past tense in Qur'an to confirm future events to denote its certainty . You will find so many events for the day of Judgment and/or for the end of the time are being expressed in past tense though these are yet to take place in future . Few examples for your perusal :
إِذَا* الشَّمْسُ كُوِّرَتْ**81:1
When (*Future Tense) the sun was Wrapped around ( **Past Tense) (on Judgment Day).
وَيَوْمَ يُنفَخُ* فِي الصُّورِ فَفَزِعَ** مَن فِي السَّمَاوَاتِ وَمَن فِي الْأَرْضِ إِلَّا مَن شَاءَ اللَّهُ ۚ وَكُلٌّ أَتَوْهُ دَاخِرِينَ27:87
And the Day on which the Trumpet will be blown(*Future Tense) and all who are in the heavens and all who are on the earth, will be terrified(** Past Tense) except him whom Allah will (exempt). And all shall come to Him humbled. (on Judgment Day)
6:27 وَلَوْ تَرَىٰ* إِذْ وُقِفُوا** عَلَى النَّارِ فَقَالُوا*** يَا لَيْتَنَا نُرَدُّ وَلَا نُكَذِّبَ بِآيَاتِ رَبِّنَا وَنَكُونَ مِنَ الْمُؤْمِنِينَ
If thou couldst see(* Future Tense) when they are stand (** Past Tense) the Fire and say ( *** Past Tense) : Oh, would that we might return! Then would we not deny the revelations of our Lord but we would be of the believers! (in Hell)
In light of the above post , you may now look into verse 17:7 and 17:104 . These two verses are interlinked with the context and background to support for one another .
إِنْ أَحْسَنتُمْ أَحْسَنتُمْ لِأَنفُسِكُمْ ۖ وَإِنْ أَسَأْتُمْ فَلَهَا ۚ فَإِذَا جَاءَ* وَعْدُ الْآخِرَةِ لِيَسُوءُوا** وُجُوهَكُمْ وَلِيَدْخُلُوا*** الْمَسْجِدَ كَمَا دَخَلُوهُ أَوَّلَ مَرَّةٍ وَلِيُتَبِّرُوا# مَا عَلَوْا تَتْبِيرًا17:07
(Saying): If ye do good, ye do good for your own souls, and if ye do evil, it is for them (in like manner). So, when the time for the second (of the judgments) came ( * Past Tense) (We roused against you others of Our slaves) to ravage you (** Future Tense), and to enter the Temple (*** Future Tense) even as they entered it the first time, and to lay waste(#Future Tense) all that they conquered with an utter wasting.
وَقُلْنَا مِن بَعْدِهِ لِبَنِي إِسْرَائِيلَ اسْكُنُوا الْأَرْضَ فَإِذَا* جَاءَ وَعْدُ** الْآخِرَةِ جِئْنَا*** بِكُمْ لَفِيفًا17:104
And We said thereafter to the Children of Israel "Dwell securely in the land (of promise)": but when(* Future Tense) the second of the warnings came to pass(** Past Tense) We gathered(*** Past tense) you together in a mingled crowd
The red part of the verse is all about future prediction as it is talking about some future moment closest to Akhirat . See below some renowned translators who translated this verse in future tense :
Moshkin Khan : And We said to the Children of Israel after him: "Dwell in the land, then, when the final and the last promise comes near [i.e. the Day of Resurrection or the descent of Christ ['Îsa (Jesus), son of Maryam (Mary) عليهما السلام on the earth], We shall bring you altogether as mixed crowd (gathered out of various nations). (Tafsir Al-Qurtubi,).
Asad : And after that We said unto the children of Israel: "Dwell now securely on earth - but [remember that] when the promise of the Last Day shall come to pass, We will bring you forth as [parts of] a motley crowd!"
Malik : Thereafter We said to the Children of Israel: "Settle down in the land and when the promise of the hereafter comes to be fulfilled, We shall assemble you all together."
Pickthall : And We said unto the Children of Israel after him: Dwell in the land; but when the promise of the Hereafter cometh to pass we shall bring you as a crowd gathered out of various nations.
However , the settlement of Jews community in Israel and their gaining fierce power above their enemies in current days confirm beyond any argument that 17:104 was really talking about the future events and now it happened already . To deny this simple fact is nothing but denying the miracle of Qur'an .