﴿ قَالَ فَبِمَآ أَغْوَيْتَنِى لَأَقْعُدَنَّ لَهُمْ صِرَٰطَكَ ٱلْمُسْتَقِيمَ ﴾

“[Whereupon Iblis] said: "Now that Thou hast thwarted me," shall most certainly lie in ambush for them all along Thy straight way,”

Said he ‘Now because You have sent me astray fa-bi-mā aghwaytanī means bi-ighwā’ik ‘for Your sending me astray’ the bā’ is for oaths and the response of the oath is the following verily I shall sit in ambush for them that is for the Children of Adam on Your straight path that is on the path that leads to You.