Bhavaa sense of identity in a world of experience. According to the Commentary, the Buddha here is referring to the states of becoming that a person who has attained the first level of awakening is still subject to. In other words, this passage is meant to discourage complacency and to give rise to the sense of heedfulness that will motivate one to continue on the path to full awakening. See SN 55:40 and The Paradox of Becoming [PDF].
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