Lug'atda "dalil" so'zi isbot, ko'rsatma yoki dalil degan ma'nolarni anglatadi. Istilohda "dalil" biror fikr, tushuncha yoki hukmning manbai yoki asosi demakdir. Har qanday qonun yoki hukm dalilga ega bo'lishi kerak, bu dalil Qur'ondan, Sunnatdan yoki Qur'on va Sunnat amal qilishga buyurgan manbalardan bo'lishi mumkin. Bu manbalar kitobning keyingi qismida muhokama qilinadi. Qur'on yoki Sunnat matnidan olingan har qanday hukm dalil hisoblanadi. Masalan, Qur'onda shunday deyilgan:

Linguistically, Daleel means a proof, indication, or evidence. As a term, Daleel means the source or evidence for a thought, concept, or a ruling. Any law or ruling must have a Daleel, which can be from Qur‟an, Sunnah, or a source, which Qur‟an and Sunnah directed us to adopt. These sources will be discussed later in the book. Any ruling from the text of either the Qur‟an or Sunnah is considered a Daleel. For example, the Qur‟an states:

"Sizlardan shunday bir jamoa bo'lsin, ular yaxshilikka (Islomga) da'vat qilsinlar, maroqli ishlarga buyursinlar va yomon ishlardan qaytarsinlar." (TMQ Oli Imron: 104)

“Let there arise out of you a group of people inviting to all that is good (Islam) and enjoining what is right and forbidding what is wrong.” (TMQ Al-Imran: 104)