Fiqh and Islamic Jurisprudence: Sources, Rulings, and Worship
Core concepts
Usul al-fiqh supplies the framework: the primary sources (Quran, Sunnah, ijma', qiyas) and the secondary tools (istihsan, maslaha, 'urf, istishab). Know the categories of ruling (ahkam): fard, wajib, mandub, mubah, makruh, haram, and the distinction between fard 'ayn (individual duty) and fard kifaya (communal duty). Understand ijtihad, taqlid, and the conditions of a mujtahid.
In worship, master the conditions (shurut), pillars (arkan), and invalidators (mubtilat) of salah, sawm, zakah, and hajj. For salah: purity, facing the qiblah, time, intention, and the sequence of standing, bowing, prostration, and sitting. For zakah: the nisab thresholds, the lunar year condition, and the eight categories of recipients. For hajj: ihram, tawaf, sa'i, and wuquf at Arafah as the indispensable rite. For transactions, know riba (excess and deferment), gharar (uncertainty), and the conditions of a valid sale.
Common traps
The classic trap is mixing shurut with arkan: intention is a condition, not a pillar. Another is confusing wajib with fard across schools, or treating sunnah mu'akkadah as obligatory. In inheritance, do not apply fixed shares (fard) before settling debts and bequests.
Worked example
A traveller omits the standing recitation and asks whether the prayer is valid. Rule of thumb: classify the element first - recitation of al-Fatiha is a pillar in most schools, so omission invalidates the unit and requires repetition; a missed sunnah act, by contrast, may be compensated by prostration of forgetfulness. Always ask: pillar, condition, or recommended act?