Attaching the Stems: How Najia Makes Hexagrams Readable

The Problem: Six Lines That Say Nothing

Take any hexagram. Hexagram 5, for instance: Xu (需), Waiting. You have six lines—three that form the lower trigram (Water, ☵) and three that form the upper trigram (Heaven, ☰). You can read the Judgment text. You can contemplate the Image. And for many people, this is the entire encounter with the I-Ching: poetic, contemplative, suggestive.

But here is the thing that the literary approach cannot give you: specificity. If you ask “Will my business deal close this month?” the image of “clouds rising to heaven” is evocative but structurally unhelpful. You cannot determine timing from it. You cannot assess whether the Wealth line is strong or weak. You cannot identify which element supports your position and which undermines it. The hexagram, as a bare pattern of six lines, is mute on these questions.

Najia solves this. It is the addressing system that makes the rest of Liu Yao divination possible. Without it, you have no Six Relatives. Without Six Relatives, you have no Useful Spirit. Without a Useful Spirit, you have no way to assess what the hexagram is telling you about the specific matter you asked about. The entire analytical apparatus collapses without this foundation.

If you have read the What is Liu Yao? article on this site, you have already encountered Najia in overview. This article goes deeper—into the actual rules, the assignment logic, and a worked example you can follow line by line.

What “Najia” Means

The term is 納甲. Na (納) means “to receive” or “to take in.” Jia (甲) is the first of the ten Heavenly Stems—but here it stands for all ten stems by synecdoche, the way we might say “learning your ABCs” to mean learning the entire alphabet. So Najia means “attaching the stems”—the process of assigning a Heavenly Stem and an Earthly Branch to each line of a hexagram.

The system is attributed to Jing Fang (京房, 77–37 BCE), the Western Han scholar who did more than anyone to systematize hexagram analysis. Jing Fang drew on earlier traditions—the Qian Zao Du (乾鑿度) and Meng Xi's hexagram-calendar mappings—but it was he who formalized the rules that the Bushi Zhengzong (卜筮正宗) transmits.

The Bushi Zhengzong preserves the Najia rules in a song (納甲裝卦歌) that begins: “乾金甲子外壬午”—Qian is Metal, inner trigram starts at Jia-Zi, outer trigram starts at Ren-Wu. Each trigram gets its own mnemonic line. The song is terse because it was designed to be memorized, not explained. So let us explain it.

The Two Systems You Need to Know

Before we can attach anything, you need the raw materials: the ten Heavenly Stems (天干) and the twelve Earthly Branches (地支).

The Ten Heavenly Stems: 甲 (Jiǎ), 乙 (Yǐ), 丙 (Bǐng), 丁 (Dīng), 戊 (Wù), 己 (Jǐ), 庚 (Gēng), 辛 (Xīn), 壬 (Rén), 癸 (Guǐ). They pair with the Five Elements: 甲乙 = Wood, 丙丁 = Fire, 戊己 = Earth, 庚辛 = Metal, 壬癸 = Water.

The Twelve Earthly Branches: 子 (Zǐ), 丑 (Chǒu), 寅 (Yín), 卯 (Mǎo), 辰 (Chén), 巳 (Sì), 午 (Wǔ), 未 (Wèi), 申 (Shēn), 酉 (Yǒu), 戌 (Xū), 亥 (Hài). Each carries an elemental association: 子 = Water, 丑 = Earth, 寅卯 = Wood, 辰 = Earth, 巳午 = Fire, 未 = Earth, 申酉 = Metal, 戌 = Earth, 亥 = Water.

In Najia, each line of a hexagram gets one Heavenly Stem and one Earthly Branch. The stem tells you which “family” the line belongs to. The branch tells you that line's specific element and its position in the temporal cycle. The branch is what actually matters for analysis—it is the branch that interacts with the Day Branch, Month Branch, and other lines' branches through the Five Element dynamics.

The Eight Palaces: Where Everything Starts

The 64 hexagrams are organized into eight groups of eight, called the Eight Palaces (八宮). Each palace is governed by one of the eight trigrams: Qian (☰), Dui (☱), Li (☲), Zhen (☳), Xun (☴), Kan (☵), Gen (☶), and Kun (☷). The palace a hexagram belongs to determines its palace element, and the palace element is the baseline against which the Six Relatives are calculated.

The Bushi Zhengzong lists them explicitly: “乾宮八卦皆屬金” —all eight hexagrams of the Qian palace belong to Metal. “坎宮八卦皆屬水”—all eight hexagrams of the Kan palace belong to Water. And so on. Qian and Dui palaces are Metal. Zhen and Xun palaces are Wood. Kun and Gen palaces are Earth. Li palace is Fire. Kan palace is Water.

When you determine the Six Relatives, you compare each line's branch element to the palace element. If the line's element generates the palace element, it is the Parent line (父母). If the palace element generates the line's element, it is the Offspring line (子孫). If they are the same element, it is a Sibling (兄弟). If the line's element controls the palace element, it is the Wealth line (妻財). If the palace element controls the line's element, it is the Authority line (官鬼). No palace, no comparison. No comparison, no Six Relatives. No Six Relatives, no reading.

The Stem Assignment Rules

Here is where most introductions wave their hands. Let us not. The rules are specific. Each of the eight pure trigrams has an assigned stem pair—one stem for when it appears as the inner (lower) trigram, and a different stem for when it appears as the outer (upper) trigram. The Najia song from the Bushi Zhengzong encodes all eight:

Notice the asymmetry. Qian uses 甲 for its inner position but 壬 for its outer position. Kun uses 乙 inner and 癸 outer. The remaining six trigrams use the same stem in both positions. This is not arbitrary—Qian and Kun are the “father” and “mother” of the trigram family, and their differentiated stems reflect that primacy. The Bushi Zhengzong takes this as given; Jing Fang's original rationale links it to the lunar cycle and the waxing and waning of yin and yang.

The Branch Assignment Rules

The stem tells you the family. The branch tells you the specific element of each line. The assignment follows two rules:

Rule 1: Yang trigrams ascend. Yin trigrams descend. The yang trigrams (Qian, Gen, Kan, Zhen) assign branches in ascending order from line 1 to line 3 (or line 4 to line 6). The yin trigrams (Kun, Dui, Li, Xun) assign branches in descending order.

Rule 2: Each trigram has a starting branch. The Najia song specifies the starting branch for each trigram position. For Qian inner, you start at 子 (Zi) and go up by twos: 子, 寅, 辰. For Qian outer, you start at 午 (Wu) and go up by twos: 午, 申, 戌. For Kun inner, you start at 未 (Wei) and descend by twos: 未, 巳, 卯. For Kun outer, you start at 丑 (Chou) and descend by twos: 丑, 亥, 酉.

Worked Example: Hexagram 5, Xu (需)

Xu (需) is Water over Heaven—Kan (☵) above, Qian (☰) below. It belongs to the Kun palace (坤宮), and its palace element is Earth. Let us attach the stems and branches line by line.

Inner trigram: Qian (☰). When Qian appears as the inner trigram, its stem is 甲 (Jia) and it starts at 子 (Zi), ascending:

• Line 1: 甲子 (Jia-Zi) — Water
• Line 2: 甲寅 (Jia-Yin) — Wood
• Line 3: 甲辰 (Jia-Chen) — Earth

Outer trigram: Kan (☵). Kan uses the stem 戊 (Wu) in both positions. Its starting branch for the outer position is 申 (Shen), ascending:

• Line 4: 戊午 (Wu-Wu) — Fire
• Line 5: 戊申 (Wu-Shen) — Metal
• Line 6: 戊戌 (Wu-Xu) — Earth

Now each line has an element. Compare each to the palace element (Earth) to derive the Six Relatives:

• Line 1: Water — Earth controls Water → Authority (官鬼)
• Line 2: Wood — Wood controls Earth → Wealth (妻財)
• Line 3: Earth — same as palace → Sibling (兄弟)
• Line 4: Fire — Fire generates Earth → Parent (父母)
• Line 5: Metal — Earth generates Metal → Offspring (子孫)
• Line 6: Earth — same as palace → Sibling (兄弟)

That is the entire process. Six lines, each with a stem, a branch, an element, and a relational role. The hexagram has gone from a mute pattern to a labeled circuit board. If you ask about finances, you look at Line 2 (the Wealth line). If you ask about career, you look at Line 1 (the Authority line). If you want to know whether the outcome has support, you check whether the Offspring line (Line 5) is generating or being suppressed.

Why This Is Not Decoration

Here is what people miss, and it is worth stating plainly: Najia is not an optional layer of ornamentation added to make hexagram readings look more sophisticated. It is the load-bearing foundation. Every subsequent concept in Liu Yao divination—the Six Relatives, the Useful Spirit (用神), line strength assessment, the relationship between the Day Branch and each line, the Monthly Commander, the void/empty calculation, the flying and hidden spirits—all of it depends on Najia having been performed first.

Without the branch assignments, you cannot determine which element each line carries. Without elements, you cannot calculate the Five Element relationships between lines. Without those relationships, the Six Relatives do not exist. Without Six Relatives, you cannot identify which line is relevant to your question. And without a relevant line, you are back to reading imagery—which is fine for contemplation, but it is not Liu Yao.

The Bushi Zhengzong opens its first volume with the Najia song for exactly this reason. It is not preliminary material to get through before the interesting parts. It is the interesting part. Every case study in the remaining thirteen volumes assumes that the reader can perform Najia without thinking about it, the way a chess player does not think about how the pieces move.

The Song Itself

The Bushi Zhengzong's Najia song (納甲裝卦歌從下裝起) runs:

乾金甲子外壬午
坎水戊寅外戊申
艮土丙辰外丙戌
震木庚子外庚午
巽木辛丑外辛未
離火己卯外己酉
坤土乙未外癸丑
兌金丁巳外丁亥

Each line encodes: the trigram, its element, the inner starting stem-branch, and the outer starting stem-branch. Once you have memorized these eight lines, you can attach the stems and branches to any of the 64 hexagrams in under a minute. The rest of the Bushi Zhengzong builds on this.

What Comes Next

Najia is step one. With the branches assigned, you can now determine the Six Relatives, locate the Subject and Object lines (世應), identify the Useful Spirit for any question, and assess line strength against the day and month. Each of these will be covered in subsequent articles in this series.

But none of them work without this. The Bushi Zhengzong places Najia first because it is first. Not in the sense of “introductory”—in the sense of “foundational.” Everything else stands on it. Learn the song. Practice the assignment. Then we can begin reading hexagrams the way the tradition actually reads them.