佛說盂蘭盆經疏 2.26

2.26

悲哀者，生育恩重如上所陳。死別隔生忽然再見，縱使顏容仍舊，亦可啼泣悲傷，況覩鬼形皮骨連立、喉中煙焰腹裏空虛，苦似倒懸命唯喘息，豈不能碎身擗踊竭氣號咷，恨罪逆之偷安、痛慈親之受苦。經標總意但曰悲哀，細察當時何疑不爾。故三藏科云摧慟，釋云：感激徹於骨髓，號叫動於天地。鉢飯往餉者，母既氣綿夕漏厄在朝飢，飢而且渴理須救濟，濟此之急飯食為先，故以鉢盛飯持餉於母。

'Filled with sorrow' means that the debt of gratitude for giving birth and raising him is heavy, as set forth above. After parting in death and being separated across lifetimes, suddenly seeing her again, even if her countenance had remained unchanged, one would still weep with grief, not to mention beholding her ghost form with skin and bones connected and standing, smoke and flame in her throat, empty inside her belly, suffering as if hung upside down, her life reduced to faint gasps—how could he not break his body, beat his breast, leap about, and wail with all his breath, lamenting that one burdened with sinful transgressions should temporarily live in vain, and agonizing over his loving mother's suffering? The sūtra marks the general meaning simply as 'filled with sorrow'; yet closely examining the situation at that time, how could it not have been so? Thus the Tripiṭaka Master's outline says 'heartbroken and distressed', explaining: 'Stirred to the very marrow of his bones, his wailing moved heaven and earth.' As for 'took a bowl filled with rice and went to feed her': his mother's breath was already as faint as an evening drip, her distress like that of morning starvation; being hungry and thirsty, she reasonably needed rescue, and to relieve such an emergency, food and drink come first, which is why he filled a bowl with rice and took it to feed his mother.