Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "Let those who are wise and understanding stand close to me, then those who are next to them in rank, and then those who are next to them in rank. Do not stand scattered here and there, for this will cause discord in your hearts. Also, refrain from the ways of the marketplace."