內煉先於外行

Before any outer ritual may be performed, the practitioner must first complete inner refinement of the Three Treasures: jing 精 (vital essence), qi 氣 (breath-energy), and shen 神 (spirit).

The text states the foundational maxim: 'The heart-mind is the ancestor of thunder' (xin wei lei zu 心為雷祖).If the practitioner's own inner qi is not concentrated, his outer talismans and incantations will not respond;

the thunder he summons is hollow, and the spirits he commands will not appear.

The text warns that practitioners who attempt outer rites without inner foundation may suffer 'inverse thunder' (ni lei 逆雷) — a backlash striking the practitioner himself.