The Messenger of Allah ﷺ said, "People, beware of injustice, for injustice will be darkness upon darkness on the Day of Resurrection."
حدثنا حسين بن علي عن زائدة عن عطاء بن السائب عن محارب بن دثار
قال رسول الله ﷺ أيها الناس اتقوا الظلم فإنه ظلمات يوم القيامة
Its isnad is sahih. It appears in Majma al-Zawaid 5:235, where it says, "Tabarani related it, and among its narrators is Ata bin Saaib, who suffered a mixing of his faculties in old age, but the rest of its narrators are narrators of the sahih." He forgot to attribute it to the Musnad, and he stated the criticism of it because of Ata without qualification. But this narration comes through Zaida bin Qudama from him, and Zaida was among those who heard from Ata early on, before his mixing of faculties began, so the isnad is sahih.Suyuti mentioned it in Jami Saghir under number 135 and attributed it to Ahmad, Tabarani, and Bayhaqi, marking it with the symbol for sahih. Munawi took issue with this in his commentary, pointing to what is mentioned in the Zawaid, and noting that Bayhaqi related it through two paths, both containing narrators who have been criticized. He then said, "What the author's symbol indicates about its being sahih is not established, and is mere recklessness." But what we have shown to be sahih about this isnad does not contradict Suyuti's position.