法華義疏 1.326

1.326

「不休息」者，上以進求為名，今從離過受稱，如救頭燃不可暫休息也。

'Anikṣiptadhura' (Never Resting): the former was named after progressive striving, while this one receives his appellation from freedom from fault, like quenching fire on one's head, which must not be rested from even for a moment.