50. This theme has already been stated at several places in the Quran. This is to impress that it is shirk to discard the commandments and the guidance of Allah and to follow the orders and guidance of any other than Allah, though one may not be professing with his tongue that there is any partner of Allah: nay, if one might be cursing others but at the same time following their orders instead of divine commandments, even then that one shall be guilty of shirk. For instance, we see that everyone in this world curses satans but still follows them. According to the Quran, in spite of cursing them, if people follow satans, they shall be guilty of setting up satans as partners with Allah. Though this will not be shirk in so many words, it will be tantamount to the practice of shirk and the Quran denounces this as shirk.
51. Generally the commentators have assigned two meanings to this. The one is the same that we have adopted in our translation and the other is this: We will cause enmity between them. That is: Their friendship in this world shall be turned into bitter enmity in the Hereafter.