Mudgalapurana 4.29.31

4.29.31

khaṃ. 4 a. 29 pāna 82) mayā manasi rājendra sandhṛtaṃ śaṅkarāt param |
vidyate na tathā kartumanyathā kartumīśvaraḥ ||

[Section 4, chapter 29, page 82] It was firmly held in my mind, O king of kings: "Higher than Śaṅkara / there is no Lord capable of doing, undoing, or altering.