Xingyi Liu He (Xingyi 6 Harmonies)

[Xue Sheng]

The Six Harmonies is divided into two sections: San Nei He or Three Internal Harmonies, and San Wai He or Three External Harmonies

Listed below is the Six Harmonies

San Nie He - Three Internal Harmonies

Xin (Heart/Spirit) leads the Yi (Intent/Mind)
Yi (Intent/Mind) leads the Qi (Energy)
Qi (Energy) leads the Li (Strength)

Chinese saying: Xin Yi Qi Li
Don't let the translation of Xin as heart of spirit fool you, it has nothing to do with spirituality

San Wai He - Three External Harmonies

The Shoulders and Hips harmonize
The Elbows and Knees harmonize
The Hands and Feet harmonize

More later on Xingyi Liu He

 

[Xue Sheng]

The Six Harmonies: (Liu He)

The hands harmonize the feet
The shoulders harmonize with the hips
Thet elbows harmonize with the knees
The heart harmonizes with the intent
The intent harmonizes with the qi
The qi harmonizes with the power

Xing Yi Nei Gong Xing Yi Health Maintenance and Internal Strength Development compiled by Dan Miller and Tim Cartmell

 

[Xue Sheng]

This one tells me much more about the topic and some points I feel appliy to js tabout every martial art out there

From "Boxing Manual Hebei Style's Five Principles and Seven Words by Jin Yunting"

The Essential Points of Xingyi Boxing’s Six Harmonies and the Extremities

The mind harmonizes the intention;
The intention harmonizes with the qi;
The qi harmonizes with the power;
These are the 3 internal harmonies.
The hands harmonize with the feet
The elbows harmonize with the knees
The shoulders harmonize with the hips
These are the 3 external harmonies.
These together are called the 6 harmonies.
The left hand harmonizes with the right foot;
The left elbow harmonizes with the right knee;
The left shoulder harmonizes with the right hip,
And conversely so on the right side.
The head harmonizes with the hands;
The hands harmonize with the body;
The body harmonizes with the foot work.
Are these not also external harmonies?
The mind harmonizes with the eyes;
The liver harmonizes with the tendons;
The spleen harmonizes with the muscles;
The lungs harmonize with the bones;
Are these not internal harmonies?
Are there then truly only six harmonies? Actually, these
Only describe the constituent parts. In the end, if one
Moves, then there are none that do not move; if one
harmonizes, then there none that do not harmonize.
The five elements and the head, torso, and four limbs can
be known from this

 

[Xue Sheng]

Just as a note

It was this part

The left hand harmonizes with the right foot;
The left elbow harmonizes with the right knee;
The left shoulder harmonizes with the right hip,
And conversely so on the right side.

That helped me figure out the power in Bengquan