(225) بَابُ الظُّلْمُ ظُلُمَاتٌ
Ibn 'Umar reported that the Prophet, may Allah bless him and granthim peace, said, "Injustice will appear as darkness on the Day of Rising."
Reference: Al-Adab Al-Mufrad 485
In-book reference: Book 28, Hadith 3
English translation: Book 28, Hadith 485