Among Buddhist texts, the Lotus Sūtra contains numerous instances of Vyākaraṇa, the prediction of becoming a Buddha in the future. In this text, there are two types of Vyākaraṇa: one is the general prediction addressed to all beings concerning their future attainment of Buddhahood, the other one is the individual prediction, given to a specific individual and specifying the concrete time of attaining Buddhahood and the exact name under which the individual will be known as a future Buddha.
All those who understand the doctrinal content set forth in the first half of the Lotus Sūtra will become bodhisattvas practising the Mahāyāna teachings. At that time, the Buddha gives them a general prediction, but they are bodhisattvas only by name and not genuine practitioners of the bodhisattva path.
In contrast, those like Śāriputra who received the individual prediction, are those who have produced the awakened mind (bodhicitta) by means of deep faith and understanding. These have at least reached the first of the ten bodhisattva stages. It is to them that the Buddha gives the individual prediction.
Therefore, this paper interprets the genuine prediction of achieving future Buddhahood as referring not to the general prediction given to titular bodhisattvas, but to the specific prediction given to those bodhisattvas who already reached the first of the ten bodhisattva stages, as a token of faith.
The Buddha's prediction given to Devadatta who didn’t have any reaction is an exceptional case which can be interpreted as follows: far from being an evil person, Devadatta actually is a great bodhisattva who merely has manifested himself as an evil person.
Zhiyi(538–597), the founder of the Tiantai tradition, provides an additional reason why prediction is given to bodhisattvas: namely, to prevent great bodhisattvas to revert to the stage of minor bodhisattvas.
Minor bodhisattvas refer to titular bodhisattvas. They have reached the ten stages of faith, but have yet to activate the mind of enlightenment.
Therefore, the bestowal of the prediction of attaining Buddhahood is a definite confirmation that one has activated the mind of enlightenment. At the same time, it is an encouragement not to lose the mind of enlightenment and to persevere in one's practice.