Musnad Ahmad 311:0

Thabit ibn al-Dahhak al-Ansari reported: The Messenger of Allah (ﷺ) said: "Whoever swears by a religion other than Islam, he is as he said." And he said: "Whoever kills himself with a piece of iron, he will be punished with it in the Fire of Hell." And he said: "Cursing a believer is like killing him." And he said: "Whoever accuses a believer of disbelief, it is like killing him." And he said: "Whoever brings a false claim to increase his wealth, Allah will not increase him except in scarcity."