CC Madhya 25.156

“muktā api līlayā vigrahaṁ kṛtvā bhagavantaṁ bhajante”
muktāḥ — liberated; api — although; līlayā — by pastimes; vigraham — the form of the Lord; kṛtvā — having installed; bhagavantam — the Supreme Personality of Godhead; bhajante — worship.
“ ‘Even a liberated soul merged in the impersonal Brahman effulgence is attracted to the pastimes of Kṛṣṇa. He thus installs a Deity and renders the Lord service.’

This is a quotation from Śaṅkarācārya’s commentary on the Nṛsiṁha-tāpanī Upaniṣad.