From Sahih Muslim (Hadith 7106):
Jabir reported that Allah's Messenger (ﷺ) said:Iblis places his throne upon water; he then sends detachments (for creating dissension) ; the nearer to him in rank are those who are most notorious in creating dissension. One of them comes and says: "I did so and so." And he says: "You have done nothing." Then one amongst them comes and says: "I did not spare so and so until I sowed the seed of discord between a husband and a wife." The Satan goes near him and says: "You have done well." A'mash said: He then embraces him
Reference: Muslim 7106