"Indeed, they are planning a plan," meaning: the polytheists are plotting against the Prophet [may Allah bless him and grant him peace].
﴿إِنَّهُم يكيدون كيداً﴾ يَعْنِي: الْمُشْرِكِينَ يَكِيدُونَ بِالنَّبِيِّ [ﷺ]
