• deva-devena — by the Lord of all the demigods
  Compound instrumental: deva (god) + deva (god). The highest possible cosmic title. The poet uses it deliberately at the moment Kṛṣṇa is doing the lowest task — foot-service. Gauḍīya: the highest stoops the lowest, because aiśvarya yields to prema.
• vipra-devena — by the Lord of the brāhmaṇas
  Compound: vipra (brāhmaṇa) + deva (lord). A second title doubling the disproportion: He whom even brāhmaṇas worship has just worshipped a brāhmaṇa. The chapter's central thesis in one compound.
• pāda-saṁvāhana — foot-massage
  Compound: pāda (foot) + saṁvāhana (rubbing, massaging). Standard servant-task. Kṛṣṇa performed it. Gauḍīya temples preserve this image as the doctrinal anchor for vipra-pūjā.
• śuśrūṣayā — with service
  Instrumental of śuśrūṣā (desire to hear / serve), from desiderative of √śru. The same term names the disciple's primary attitude toward the guru. The verse reverses it: Bhagavān treats Sudāmā with disciple-toward-guru śuśrūṣā.
• deva-vat — like a demigod
  deva (god) + vat (like, suffix of comparison). Kṛṣṇa treated the brāhmaṇa as if Sudāmā were a deva. The whole hierarchy is inverted in one suffix.

• Where could my own greatness be exercised by service rather than receiving?
• Whose feet — literal or metaphorical — could I serve today?

The Lord of all the devas — the One the brāhmaṇas worship — knelt down and pressed His friend's feet. To Sudāmā this was the photograph of brahmaṇya-deva that no scripture-verse could have given him: deva-deva washing the dust off his soles like a junior at the ashram.