(We shall attend to you,) means, `We shall judge you,' while Al-Bukhari said that it means, "We shall recompense you. Surely, nothing will busy Allah from attending to anything else." This type of speech pattern is common in the Arabic language. For example, one would say, "I will attend to you," even when one is not busy with anything else. Allah's saying;
أَيُّهَا الثَّقَلاَنِ
(O you Thaqalan!) refers to the humans and the Jinns, as in the Hadith;
«يَسْمَعُهَا كُلُّ شَيْءٍ إِلَّا الثَّقَلَيْن»
(Everyone will be able to hear it, except the Thaqalayn.) In another narration that explains it, the Prophet said,
يُرْسَلُ عَلَيْكُمَا شُوَاظٌ مِّن نَّارٍ وَنُحَاسٌ فَلَا تَنتَصِرَانِ (A flame of fire and a smoke will be loosed against you, and you will not [ be able ] to defend... 55:35) Sayyidna Ibn ` Abbas ؓ and other leading authorities on Qur'anic exegesis have said that the word shuwaz with refers to 'flame or fire without smoke' and the word nuhas refers to 'smoke in which there is no flame'. This verse too addresses the two species of creation, the jinns and mankind. It addresses them and describes how fire and smoke will be unleashed against them. The verse could mean that after the reckoning is over, and the disbelievers are sent to the Hell, they will experience two different types of punishment. In some places there will be only fire and flame, with no smoke at all. In other places there will be only smoke and no flame or fire. Other Qur'anic exegetes regard this verse as a supplement to the preceding one, and assign the following meaning to it: O jinn and mankind, it is not within your power to cross the bounds of the heavens. If you do attempt to escape on the Day of Resurrection, then the angels [ including those guarding the Hellfire ] will bring you back by directing the flames of fire and smoke. The verb فَلَا تَنتَصِرَانِ fala-tantasiran is derived from اِنتِصَار intisar which means 'to help someone to defend him against a calamity' and thus the words فَلَا تَنتَصِرَانِ fala-tantasiran signify that the jinns and mankind will not be able to help each other against Divine punishment, try as they might.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 36–44
The present world is a place of trial. So long as the period of testing lasts, everybody has the opportunity to be as arrogant as he pleases. But, in spite of this complete freedom, no jinn or human being has the power to go beyond the limits of the universe. This fact itself is enough to prove that man is completely in the grip of God. On the expiry of the test period, when He starts seizing hold of people, it will not be possible for anybody to save himself.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.