Abd al-Rahman bin Abdullah bin Mas'ud narrates from Sayyiduna Abdullah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) gathered us, and I was the last of them to come to him; we were forty men. He (peace and blessings be upon him) said: "You will attain your goals, you will be helped, and victory will be granted to you. Whoever lives to see that, let him fear Allah, enjoin what is good and forbid what is evil, and maintain the ties of kinship. And whoever lies about me deliberately, let him take his seat in the Fire."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5619