"I did not make them witness the creation of the heavens and the earth, nor the creation of themselves." This is because the polytheists said: "The angels are the daughters of Allah." That is: I did not make them witness any of that. "And I would not have taken the misguiders as assistants," meaning: helpers.
﴿مَا أشهدتهم خلق السَّمَاوَات وَالْأَرْض وَلَا خلق أنفسهم﴾ وَذَلِكَ أَنَّ الْمُشْرِكِينَ قَالُوا: إِنَّ الْمَلَائِكَةَ بَنَاتُ اللَّهِ؛ أَيْ: مَا أَشْهَدْتُهُمْ شَيْئًا مِنْ ذَلِكَ ﴿وَمَا كنت متخذ المضلين عضدا﴾ أَي: أعوانا