Bhagavad Gita · Purushottama YogaChapter 15, Shloka 2 (15.2)

Shankaracharya. adhaḥ manuṣyādibhyo yāvat sthāvaram ūrdhvaṃ ca yāvat brahmaṇaḥ … dhāma — below down to the immobile beings, above up to the abode of Brahma; guṇaiḥ sattvarajastamobhiḥ pravṛddhāḥ sthūlīkṛtāḥ; viṣayāḥ śabdādayaḥ pravālāḥ iva — sense-objects such as sound are like shoots.

Acharya Ramanuja. brahmalokamūlasya asya vṛkṣasya manuṣyāgrasya adhaḥ manuṣyaloke mūlāni anusaṃtatāni, tāni ca karmānubandhīni — of this tree, rooted in Brahmaloka with humans at its tip, the roots in the form of karma spread below in the world of humans; karmāṇi eva anubandhīni mūlāni.

Shridhara Swami. The branches = jivas: teṣu ca ye duṣkṛtinas te 'dhaḥ … sukṛtinaś cordhvaṃ devādiyoniṣu — spread below and above according to their karma (the traditional reading of rebirth). Guṇaiḥ … jalasecanair iva — the gunas make the branches grow as watering does; viṣayā rūpādayaḥ pravālāḥ — sense-objects are the shoots.

Madhusudana Saraswati. Agrees with Shridhara; and on the boundary of above and below: manuṣyatvād ārabhya — beginning from human birth, both upward and downward.

Madhvacharya. A different picture: mūlāni bhagavadrūpādīni — the roots are the forms of the Lord and so on; bhagavān api karmānubandhena hi phalaṃ dadāti — even the Lord gives results only in accordance with karma.