Umm Darda' reported on the authority of Abu Darda' as saying: I heard Allah's Messenger (ﷺ) as saying: The invoker of curse would neither be witness nor intercessor on the Day of Resurrection.
Hadith ReferenceSahih Muslim / The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship / Hadith: 2598