( أَفَأَمِنُوا مَكْرَ اللَّهِ) (Then did they feel secure from the plan of Allah?): Allah (swt) does not make malicious plots. Plotting can be of both malicious or righteous. Allah (swt) says:

  وَلَا يَحِيقُ الْمَكْرُ السَّيِّئُ إِلَّا بِأَهْلِهِ

(but the evil plot does not encompass except its own people)

(Faatir: 43)

Evil plotting is a form of scheming or strategic planning done discreetly. Here, Allah (swt) makes it clear that they scheme and Allah (swt) in turn outmaneuvers their schemes. This is the divine form of planning, the one that serves good as it thwarts their evil plotting. (but the evil plot does not encompass except its own people).