The Quran
26:192 This is a revelation from the Lord of the universe. 26:193 The Honest Spirit (Gabriel) came down with it. 26:194 To reveal it into your heart, that you may be one of the warners. 26:195 In a perfect Arabic tongue. 26:196 It has been prophesied in the books of previous generations. 26:197 Is it not a sufficient sign for them that it was known to the scholars among the Children of Israel?
Why does God refer to Gabriel as Honest in 26:193, are not all angels honest?
Is Gabriel an angel?
2:98 Anyone who opposes GOD, and His angels, and His messengers, and Gabriel and Michael, should know that GOD opposes the disbelievers.