Shaytan Lured the Idolators to Kill Their Children
Allah says, just as the Shayatin lured the idolators to assign a share for Allah from what He created of agriculture and cattle - and a share for the idols, they also made it seem fair for them to kill their children, for fear of poverty, and burying their daughters alive, for fear of dishonor. `Ali bin Abi Talhah reported from Ibn `Abbas that he commented;
وَكَذَلِكَ زَيَّنَ لِكَثِيرٍ مِّنَ الْمُشْرِكِينَ قَتْلَ أَوْلَـدِهِمْ شُرَكَآؤُهُمْ
(And so to many of the idolators, their "partners" have made fair seeming the killing of their children...) "They make killing their children attractive to them." Mujahid said, "Idolators' partners among the devils ordered them to bury their children for fear of poverty." As-Suddi said, "The devils commanded them to kill their daughters so that they,
لِيُرْدُوهُمْ
(lead them to their own destruction), and to,
وَلِيَلْبِسُواْ عَلَيْهِمْ دِينَهُمْ
(cause confusion in their religion.)" Allah said,
وَلَوْ شَآءَ اللَّهُ مَا فَعَلُوهُ
(And if Allah had willed, they would not have done so.) meaning, all this occurred by Allah's leave, will and decree, but He dislikes these practices, and He has the perfect wisdom in every decree. He is never questioned about what He does, but they all will be questioned.
فَذَرْهُمْ وَمَا يَفْتَرُونَ
(So leave them alone with their fabrications.) meaning, avoid and abandon them and what they do, for Allah will judge between you and them.
Tafsir Ibn Kathir (abridged, English).