Hexagram 4 of 64

☶☵ Youthful Folly

Inexperience meeting a problem it does not yet understand.

Upper trigram

Mountain · Gen

Stillness and limit.

FamilyYoungest son
ElementEarth

Lower trigram

Water · Kan

Danger and depth.

FamilyMiddle son
ElementWater

The image

Mountain above, Water below.

Mountain over Water: stillness and limit meeting danger and depth.

That combination is the whole meaning of hexagram 4. Nothing about it is arbitrary — change either trigram and you get a different hexagram with a different reading, which is why the 64 form a system rather than a list.