The Stories of the Lotus Sutra, p 234-235In ancient India placing one’s hand on the head of another apparently was a sign of trust. Clearly something like that is intended here – but perhaps something more is involved. Though not in this chapter, in various places in the Dharma Flower Sutra, Shakyamuni Buddha has said that he is the father of this world. Further, bodhisattvas are regarded as children of the Buddha. There is, in other words, a kind of familial relation, a relation of affection between the Buddha and bodhisattvas. Here, the placing of his hand on the heads of bodhisattvas indicates that the relationship is not only one of trust in a formal sense but displays a religious faith which goes beyond calculations of ability and such. Just as in early chapters of the Sutra he has assured shravakas of becoming buddhas, here the Buddha assures bodhisattvas that they can do the job that needs to be done.
The bodhisattvas, in turn, assure the Buddha that they will indeed carry on his ministry of spreading the Dharma. In other words, the relationship of trust between the Buddha and the bodhisattvas is a mutual one, based on personal assurance. The Buddha assures the bodhisattvas that they can do what needs to be done and they assure him that they will do it.