《黄帝内经·灵枢·官针》
脉络分布在浅部而现于外的，就不能直接针刺，必须先按压隔绝其脉，使血脉停留然后才可以进行针刺。只有这样，才不致出血，也就不使精气外泄，而只将邪气去除。
脉浅者，勿刺，按绝其脉乃刺之，无令精出，独出其邪气耳。
Meridians and collaterals that are located shallow and visible on the surface cannot be punctured directly, and must be pressed first to isolate them and make the blood stop flowing before acupuncture can be performed. Only in this way can bleeding be prevented, so that the vital energy is not lost, and only the pathogenic qi is removed.