Does this also not help to understand the Object Pronoun under debate?
أَمْ لَمْ يَعْرِفُوا رَسُولَهُمْ فَهُمْ لَهُ مُنْكِرُونَ
Thank you for quoting this aayat, here it is.
23:69
اَمۡ لَمۡ یَعۡرِفُوۡا رَسُوۡلَہُمۡ فَہُمۡ لَہٗ مُنۡکِرُوۡنَ 23:69 Or did they not know
their messenger? For they are in denial
of him.
You can look at the pattern, when the aayat talks about Rasool then the HU is referring to Rasool.12:58
وَ جَآءَ اِخۡوَۃُ یُوۡسُفَ فَدَخَلُوۡا عَلَیۡہِ فَعَرَفَہُمۡ وَ ہُمۡ لَہٗ مُنۡکِرُوۡنَ12:58 And the brothers of
Yousuf came and entered upon him, and he recognized them, but they did not recognize
him.
You see how HU is referring to Yousuf as it is mentioned earlier in the same aayat?7:27
یٰبَنِیۡۤ اٰدَمَ لَا یَفۡتِنَنَّکُمُ الشَّیۡطٰنُ کَمَاۤ اَخۡرَجَ اَبَوَیۡکُمۡ مِّنَ الۡجَنَّۃِ یَنۡزِعُ عَنۡہُمَا لِبَاسَہُمَا لِیُرِیَہُمَا سَوۡاٰتِہِمَا ؕ اِنَّہٗ یَرٰىکُمۡ ہُوَ وَ قَبِیۡلُہٗ مِنۡ حَیۡثُ لَا تَرَوۡنَہُمۡ ؕ اِنَّا جَعَلۡنَا الشَّیٰطِیۡنَ اَوۡلِیَآءَ لِلَّذِیۡنَ لَا یُؤۡمِنُوۡنَ7:27 O Children of Adam, do not let
the Shaitaan afflict you as he evicted your parents from the paradise; he removes from them their garments to show them their bodies.
He and
his tribe see you from where you do not see them. We have made the devils as allies for those who do not believe.
Even in a long aayat HU is referring to the context of the aayat.Following aayaats shows that HU is referring to non-humans.7:146
سَاَصۡرِفُ عَنۡ اٰیٰتِیَ الَّذِیۡنَ یَتَکَبَّرُوۡنَ فِی الۡاَرۡضِ بِغَیۡرِ الۡحَقِّ ؕ وَ اِنۡ یَّرَوۡا کُلَّ اٰیَۃٍ لَّا یُؤۡمِنُوۡا بِہَا ۚ وَ اِنۡ یَّرَوۡا سَبِیۡلَ الرُّشۡدِ لَا یَتَّخِذُوۡہُ سَبِیۡلًا ۚ وَ اِنۡ یَّرَوۡا سَبِیۡلَ الۡغَیِّ یَتَّخِذُوۡہُ سَبِیۡلًا ؕ ذٰلِکَ بِاَنَّہُمۡ کَذَّبُوۡا بِاٰیٰتِنَا وَ کَانُوۡا عَنۡہَا غٰفِلِیۡنَ7:146 I will turn away from My revelations those who are arrogant on the earth without right, and if they see every sign they do not believe in it, and if they see
the path of guidance they do not take
it as a path; and if they see
the path of mischief, they take
it as a path. That is because they have denied Our revelations and were heedless of them.
Again HU is referring to the context mentioned in the same aayat.16:14
وَ ہُوَ الَّذِیۡ سَخَّرَ الۡبَحۡرَ لِتَاۡکُلُوۡا مِنۡہُ لَحۡمًا طَرِیًّا وَّ تَسۡتَخۡرِجُوۡا مِنۡہُ حِلۡیَۃً تَلۡبَسُوۡنَہَا ۚ وَ تَرَی الۡفُلۡکَ مَوَاخِرَ فِیۡہِ وَ لِتَبۡتَغُوۡا مِنۡ فَضۡلِہٖ وَ لَعَلَّکُمۡ تَشۡکُرُوۡنَ 16:14 And He is the One who has commissioned
the ocean, that you may eat from
it a tender meat, and that you may extract from
it pearls that you wear. And you see the ships flowing through it, so that you may seek from His bounty, and that you may be thankful.
Is it possible to drag Muhammed in and try to fit in place of HU in all the aayaats above? If not, then what is the problem in understanding 6:20? Where did Muhammed came in between in 6:20 when it clearly talks about AlKitaab?6:20
اَلَّذِیۡنَ اٰتَیۡنٰہُمُ الۡکِتٰبَ یَعۡرِفُوۡنَہٗ کَمَا یَعۡرِفُوۡنَ اَبۡنَآءَہُمۡ ۘ اَلَّذِیۡنَ خَسِرُوۡۤا اَنۡفُسَہُمۡ فَہُمۡ لَا یُؤۡمِنُوۡنَ6:20 Those to whom We have given
the Book know it as they know their children. Those who lost their souls, they do not believe.
BTW, what is the use of knowing Muhammed as we know our sons? If we know AlKitaab as we know our sons, that will be really help to save us on each and every step we take in our life.May Allah increase us in knowledge and guide us to His true path

mmKhan