Wandering is one way in which Dhamma was spread throughout India and beyond by Bhikkhus. They do not have many possessions, unlike householders who must have a lot of things, so they can come and go easily. The Buddha compared the Bhikkhu to a swan, a bird that is plain and unadorned but capable of flying very far and strongly. The layperson is compared to the peacock, beautiful but burdened by its beauty and therefore slow and unable to fly long distances. It is for this reason that Dhamma was spread far and wide mostly by Bhikkhus. It is very rare to read of a layman or woman propagating the Dhamma in distant lands for usually they would have their families to look after. Of course, there have always been learned lay Buddhists, and those who have been able to practise meditation deeply, but they have rarely travelled far. Their influence was usually limited to their own towns or villages where they would be foremost among the supporters of the local Teacher-monks and leaders of the lay Buddhist community.
Banner of the Arahants:
Buddhist Monks and Nuns from the Buddha's time till now
by Bhikkhu Khantipalo