佛說盂蘭盆經疏 2.39

2.39

Question: Since the time of Dīpaṅkara Buddha, Maudgalyāyana's mothers through various lives were not one and the same; why did he rescue only that Qingti? Answer: Qingti had deep affinities with Maudgalyāyana, and became his mother again in this lifetime. He was merely rescuing the mother who gave birth to him in this life, not rescuing that Qingti of distant lifetimes. Other treatises' claims are all due to a lack of understanding.