وَلَهُ ۥ مَن فِى ٱلسَّمَـٰوَٲتِ وَٱلۡأَرۡضِۚ وَمَنۡ عِندَهُ ۥ لَا يَسۡتَكۡبِرُونَ عَنۡ عِبَادَتِهِۦ وَلَا يَسۡتَحۡسِرُونَ (١٩) يُسَبِّحُونَ ٱلَّيۡلَ وَٱلنَّہَارَ لَا يَفۡتُرُونَ (٢٠)
لَا يَسۡبِقُونَهُ ۥ بِٱلۡقَوۡلِ وَهُم بِأَمۡرِهِۦ يَعۡمَلُونَ (٢٧) يَعۡلَمُ مَا بَيۡنَ أَيۡدِيہِمۡ وَمَا خَلۡفَهُمۡ وَلَا يَشۡفَعُونَ إِلَّا لِمَنِ ٱرۡتَضَىٰ وَهُم مِّنۡ خَشۡيَتِهِۦ مُشۡفِقُونَ (٢٨) ۞ وَمَن يَقُلۡ مِنۡہُمۡ إِنِّىٓ إِلَـٰهٌ۬ مِّن دُونِهِۦ فَذَٲلِكَ نَجۡزِيهِ جَهَنَّمَۚ كَذَٲلِكَ نَجۡزِى ٱلظَّـٰلِمِينَ (٢٩)
To Him belongs all (creatures) in the heavens and on earth: even those who are in His (very) Presence are not too proud to serve Him, nor are they (ever) weary (of His service): (19) They celebrate His praises night and day, nor do they ever flag or intermit. (20)
They speak not until He hath spoken, and they act by His command. (27) He knoweth what is before them and what is behind them, and they cannot intercede except for him whom He accepteth, and they quake for awe of Him. (28) And one of them who should say: Lo! I am a God beside Him, that one We should repay with hell. Thus We Repay wrong-doers. (29)
AND IN SURAH ZUMAR 65: THE SIN OF SHIRK:
But it has already been revealed to thee, as it was to those before thee― “If thou wert to join (gods with Allah), truly fruitless will be thy work (in life), and thou wilt surely be in the ranks of those who lose (all spiritual good).” (65)
SUMMARY OF THE TAFSEER BY DR. FARHAT HASHMI (translated)
Allah Subhanawataala is teaching the children of Adam by example of the angels. How thye are humble in their worship, how they do hamd day and night and do not fatigue or get bored.
How they obey Allahs command, and even though they are always in prayer, they do not have the right or ability to intercede on behalf of anyone except by the leave of Allah Himself.
The last ayah is a strong warning to serve as a deterrent of Shirk in all forms, hidden or overt!
In the final analysis:
The slaves of Allah worship Him and Him alone and do not even think or go near anything or anyone by word or action that may involve them in Shirk.