Sayyiduna Abu Dharr and Sayyiduna Salman (may Allah be pleased with them both) narrate that the Messenger of Allah (peace and blessings be upon him) took hold of the hand of Sayyiduna Ali (may Allah be pleased with him) and said: "This is the first to believe in me, and he will be the first to shake hands with me on the Day of Resurrection. He is the greatest Siddiq (the truthful one), and he is the Faruq of this Ummah, distinguishing between truth and falsehood. He is the leader of the believers, and wealth is the leader of the wrongdoer."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6159