維摩義記 2.43

2.43

問曰：若使一生天上後生人間而得成佛名一生者，有須陀洹一生天上人間而涅槃者，十四生中幾生所攝？釋言：此十四生中名為二生。若爾，彌勒亦應同彼，何得言一？釋言：應齊而說異者，以其所望不同故爾。彼須陀洹望於身盡餘涅槃，故受兩身，即是二生。如彌勒等，望於佛身，後生人間即是佛身，對彼身故偏名兜率一報為一。

Question: If being born for one lifetime in heaven and later born in the human realm to attain Buddhahood is called "one lifetime", then for a srotāpanna who is born once in heaven and once in the human realm to enter nirvāṇa, into how many lifetimes of the fourteen lifetimes is this included? Explanation: Among these fourteen lifetimes, this is called two lifetimes. If that is so, Maitreya should also be the same as that; how can one say "one"? Explanation: They ought to be equal, yet are spoken of differently because what they are viewed in relation to is not the same. That srotāpanna is viewed in relation to the nirvāṇa with remainder upon the exhaustion of the body; therefore, receiving two bodies constitutes two lifetimes. In the case of Maitreya and others, they are viewed in relation to the Buddha-body; the subsequent birth in the human realm is the Buddha-body itself, and in contrast to that body, only that single recompense in Tuṣita is specifically called "one".