Bhagavad Gita · Bhakti YogaChapter 12, Shloka 9 (12.9)

Shankaracharya. cittasya ekasmin ālambane sarvataḥ samāhṛtya punaḥ punaḥ sthāpanam abhyāsaḥ — gathering the mind in from every side and setting it again and again on one support — this is practice.

Acharya Ramanuja. atha sahasā eva mayi sthiraṃ samādhātuṃ na śaknoṣi — if you cannot make it steady all at once; svābhāvika…asaṃkhyeyakalyāṇaguṇasāgare … mayi niratiśayapremagarbhasmṛtyabhyāsayogena — on me, the ocean of countless auspicious qualities, through the practice of remembrance filled with love.

Madhusudana Saraswati. He maps out the ladder: pratimādau bāhye bhagavaddhyānābhyāsas tadaśaktau bhāgavatadharmānuṣṭhānaṃ tadaśaktau sarvakarmaphalatyāga — first, practising meditation on an outer support such as a sacred image; if that is not possible, the bhagavata dharma (service and kirtan); if even that is not possible, giving up the fruits of all actions. And a lovely point on the address "Dhananjaya": bahūn śatrūn jitvā dhanam āhṛtavān asi … evaṃ manaḥśatruṃ jitvā tattvajñānadhanam āhariṣyasi — just as you conquered enemies and brought back wealth, so you will conquer the enemy that is the mind and bring back the wealth of the knowledge of truth.

Shridhar Swami. The simple meaning of practice: vikṣiptaṃ cittaṃ punaḥ pratyāhṛtya mamānusmaraṇalakṣaṇo yogābhyāsaḥ — bringing the wandering mind back again and again to remember me — this is the yoga of practice.