"Thus We have inserted it" (Al-Shu‘ara: 200), meaning: We have inserted the denial of it into the hearts of the criminals, the polytheists.
﴿كَذَلِك سلكناه﴾ أَيْ: سَلَكْنَا التَّكْذِيبَ بِهِ ﴿فِي قُلُوب الْمُجْرمين﴾ الْمُشْركين