Sumantu is a disciple of Vyasa, custodian of the Atharva Veda: 'atharvāṅgirasām āsīt sumantur dāruṇo muniḥ' (SB 1.4.22).

Alone in the beginning, His power asleep, His sight awake

Maitreya's account: in the beginning the Lord alone was, the Self of selves, all-pervading; then He was the seer but saw nothing to be seen, and took Himself as though not existent — 'mene asantam iva AtmAnaM supta-shaktir asupta-dR^ik' (SB 3.5.23-24).

Removed Arjuna's wrong understanding by the science of the Self

'kumatim aharad atma-vidyaya yash carana-ratih paramasya' (SB 1.9.36) — the teaching to Arjuna who had turned from slaying his kin.

Teacher of the worlds (jagad-guru)

In the assembly Krishna is called the teacher of the worlds: 'jagad-gurur yAni jagAda kR^iShNaH' (SB 3.1.9).

Krishna — expands as kala — Manus

The Manus are kalas of Hari (SB 1.3.27). Evidence: EXPLICIT.