Help with Tables?

Can someone tell me why this work's if I just do if msg == args but not if msg == Prefix.." "..args?

local Prefix = ";"

function MakeCommand(args)
	game.Players.PlayerAdded:connect(function(plr)
		plr.Chatted:connect(function(msg)
			if msg == Prefix.." "..args then
				local m = Instance.new("Message",workspace)
				m.Text = "Hi there "..plr.Name
			end
		end)
	end)
end

MakeCommand("hi")