'Not this either,' Markus concluded with his eyes closed. He was currently sitting in a cross-legged posture in his room. He'd entered seclusion two weeks back and had effectively shut himself off from all outside communication. Markus could feel that he was at the cusp of a breakthrough. It was so close he could grab it, but it was yet to enter his reach. To bridge this gap, Markus considered a long-standing tradition amongst cultivators nearing advancement: Closed-Door Cultivation.
Usually, the phrase closed-door is a placeholder implying isolation from all forms of intrusions and disturbances. It means to espouse an optimal environment for a cultivator to piece together scattered insights to develop new, more robust ones and as a result, achieve a breakthrough in their cultivation. It didn't necessitate foregoing nourishment as it was often counterproductive to the assimilation process.