Explanation of the hadith
If a man says: "People are ruined" with the intention of degrading and belittling them and considering himself in a higher rank and better position than them, he shall be the most ruined among them. The wording of another narration reads: "...he man will ruin people." In this case, it means this man is a reason for their being ruined, because he causes them to despair and lose hope in the mercy of Allah. By doing so, he prevents them from returning to Allah in repentance and pushes them in the way of despair until they become ruined.