The madhyama-adhikari wants to see that not a moment is wasted without Krsna consciousness. That is madhyama-adhikari. Avyartha-kalatvam [Cc. Madhya 23.18-19]. He’s always careful that “Whether I am spoiling the valuable time of my life.” That is the first qualification of madhyama-adhikari. Avyartha-kalatvam. Because we have got very short period, living period. We do not know when we shall die. There is no certainty. Foolish people may think that “I shall live forever,” but that is foolishness. Life is very transient. At any moment we can die. Therefore those who are advanced devotees want to see that “I have got very short period of life at my disposal…” Therefore, he is very anxious to utilize every moment for advancing in Krsna consciousness. That is madhyama-adhikari.

From Srila Prabhupada’s lecture on Srimad-Bhagavatam 3.25.36 — December 5, 1974, Bombay