The matn’s calculation chapter — ta’shilul-masa’il. The procedure is the same one used in the two previous bundles (it is genuinely universal); what is distinctive to the Zayd system: base numbers 18 and 36 are permanent residents, not guests, because the grandfather chapter is always alive.
The 7-step procedure
flowchart TB
classDef proses fill:#713f12,stroke:#ca8a04,color:#fef9c3
classDef furud fill:#1e3a8a,stroke:#3b82f6,color:#dbeafe
classDef asabah fill:#134e4a,stroke:#14b8a6,color:#ccfbf1
classDef hasil fill:#3b0764,stroke:#a855f7,color:#f3e8ff
S1["1. Filter impediments & hajb (chapters 02, 04)"]:::proses --> S2["2. Status: fixed shares / 'ashabah /<br/>grandfather case (chapters 03, 04, 08)"]:::furud
S2 --> S3["3. Base number = LCM of denominators"]:::proses
S3 --> S4["4. Fixed-share portions"]:::furud
S4 --> S5["5. Remainder → 'ashabah (2:1)"]:::asabah
S5 --> S6["6. Correction: 'awl (chapter 07) /<br/>tashih (chapter 06) —<br/>remainder without 'ashabah → bayt al-mal (chapter 07)"]:::proses
S6 --> S7["7. Convert to rupiah + check the total"]:::hasil
Base numbers: the seven standard ones + two specific to the grandfather chapter
| Who is present | Base |
|---|---|
| 1/2 only | 2 |
| 1/3 · 2/3 | 3 |
| 1/4 (± 1/2) | 4 |
| 1/6 and its combinations | 6 |
| 1/8 (± 1/2) | 8 |
| 1/4 × family in thirds/sixths | 12 |
| 1/8 × family in thirds/sixths | 24 |
| Grandfather’s 1/3 of the remainder on a base of 6 | 18 |
| Grandfather’s 1/3 of the remainder on a base of 12 | 36 |
The last two rows appear only in the grandfather-with-siblings chapter (chapter 08) — and because the matn follows the Zayd system, both are a permanent part of the curriculum, not a footnote. Another rule: all-‘ashabah-without-fixed-shares → base = number of heads (male counts as 2, female as 1).
A fully worked example
A deceased woman leaves behind a husband, a mother, and 2 sons. Net estate Rp 360,000,000.
- Filter: complete, nobody is excluded.
- Status: husband 1/4 (there is descent); mother 1/6; 2 sons ‘ashabah.
- Base: LCM(4,6) = 12.
- Shares: husband 3, mother 2.
- Remainder: 7 for 2 heads → does not divide evenly → tashih (chapter 06): ×2 → base 24: husband 6, mother 4, each son 7.
- Rupiah: 1 share = 15m.
Base number: 12 → tashih ×2 = 24 Estate: Rp 360,000,000
─────────────────────────────────────────────────────────
Heirs Status Shares/12 Shares/24 Rupiah
husband 1/4 3 6 90,000,000
mother 1/6 2 4 60,000,000
son (1) 'ashabah ─┐ 7 105,000,000
son (2) 'ashabah 7┘ 7 105,000,000
─────────────────────────────────────────────────────────
Total 12 24 360,000,000 ✓Mandatory habit: total the rupiah column, and check it matches the estate.
Three possible outcomes after the fixed shares
- Exactly divides out — done.
- Remainder + ‘ashabah — the remainder goes to ‘ashabah.
- Doesn’t divide evenly: the fixed shares exceed the base → ‘awl (chapter 07); a remainder without ‘ashabah → per the matn, bayt al-mal (chapter 07 — this is where classical Shafi’i parts ways with radd); shares that don’t divide evenly among heads → tashih (chapter 06).
Sources: Matn ar-Rahbiyyah, chapter on al-hisab/ta’shilul-masa’il (Shamela 11372); Sharh al-Hazimi (Shamela 36125). Full list in 15-references.