Al-Baqarah - 2:34

وَإِذْ قُلْنَا لِلْمَلاَئِكَةِ اسْجُدُواْ لآدَمَ فَسَجَدُواْ إِلاَّ إِبْلِيسَ أَبَى وَاسْتَكْبَرَ وَكَانَ مِنَ الْكَافِرِينَ
[2:34]
And when We said to the angels: Make obeisance to Adam they did obeisance, but Iblis (did it not). He refused and he was proud, and he was one of the unbelievers.
And behold, We said to the angels: "Bow down to Adam" and they bowed down. Not so Iblis: he refused and was haughty: He was of those who reject Faith.
And when We said unto the angels: Prostrate yourselves before Adam, they fell prostrate, all save Iblis. He demurred through pride, and so became a disbeliever.