What is the difference between the statement of Iblis: "Because You have put me in error, I will surely sit in wait for them on Your straight path" and the statement of Adam: "Are you blaming me for a matter that Allah has already decreed for me?"

The belief of Ahl al-Sunnah regarding the verse: (He said: "Because You have sent me astray, I will surely sit in wait for them on Your straight path") is that Allah led Iblis astray and created disbelief within him. Thus, the misguidance is attributed to Allah because everything in existence is created by Him and originates from His will. Allah willed Iblis's misguidance as a matter of divine decree (qadar), not as a matter of religious law (shar'). As for Adam's reliance on divine decree in the hadith of Moses's argumentation, it was in relation to the calamity, not the sin. Divine decree is invoked in calamities, but it is not invoked in sins and faults.