Maana ya kilugha ya Qiyas ni kukadiria, kupima, au kubainisha urefu, uzito, au ubora wa kitu fulani, ndiyo maana mizani huitwa miqyas. Kama istilahi ya kisheria, wengi wa Ulamaa wamefafanua Qiyas kuwa ni, „kutumia hukumu (Hukm) ya kisa cha asili (asl) kwa kisa kipya (far') ambacho sheria haijatoa hukumu yake, kwa sababu ya kiini cha sababu ('Illa) kilicho shirikishi kwa vyote viwili.‟11

The linguistic meaning of Qiyas is means estimation, measuring or ascertaining the length, weight, or quality of something, which is why scales are called miqyas. As a juristic term Qiyas the majority of Ulema have defined Qiyas as, „the application to a new case (far'), on which the law is silent, of the ruling (Hukm) of an original case (asl) because of the effective reason ('Illa) which is in common to both.‟11

Ifuatayo ni mfano wa Qiyas:

The following is an example of Qiyas:

"Enyi mlioamini! Mnapoadhiniwa kwa Sala siku ya kukusanyika (Ijumaa), harakisheni kwenda kumkumbuka Mwenyezi Mungu, na acheni biashara zote. Hii ni bora kwenu, kama mkijua. Na sala itakapokwisha, tawanyikeni katika ardhi mtafute fadhila za Mwenyezi Mungu, na mkumbuke Mwenyezi Mungu sana, ili mpate kufaulu."

“O you who have attained faith! When the call to prayer is sounded on the day of congregation (Friday), hasten to the remembrance of Allah, and leave all worldly commerce: this is for your own good, if you but knew it. And when the prayer is ended, disperse freely on Earth and seek to obtain Allah‟s bounty; but remember Allah often, so that you might attain to a happy state!” (TMQ al-Juma‟: 9-10)

Aya hiyo inataja kwamba, wakati adhana ya swala inapotolewa, mtu anapaswa kuacha biashara zote za kidunia. Aya hiyo haitaji kuacha vitendo kama kula, kupumzika, au chochote kingine isipokuwa kufanya biashara. Aya hiyo inataja pia kwamba swala ikimalizika, watawanyike na kutafuta fadhila ya Allah. Hii ina maana kwamba kuna sababu ya kuacha biashara, kwa kuwa tusipoacha, tutashughulika nayo na tutasahau swala.

The Ayah mentions that, when the call to prayer is given, one should disengage from all worldly commerce. The Ayah doesn‟t mention to stop such acts as eating, resting, or anything else other than conducting business. The Ayah mentions that when the prayer is over, disperse and seek Allah‟s bounty. This means that there is a reason to leave the commerce, being that if we do not, then we will be preoccupied and will forget the prayer.

Utumiaji wa Qiyas kwa mfano huu ungekuwa kwa shughuli yoyote nyingine mbali na biashara. Hii ni kwa sababu ya 'Illah (sababu ya kukosa swala ya Ijumaa) hutokea kutokana na shughuli hizi pia. Kwa hiyo, kufanya kazi, kucheza, kula n.k. vinakatazwa wakati wa Ijumaa, kwa sababu shughuli hizi zote huwazuia Waislamu kutekeleza swala ya Ijumaa.

The application of Qiyas for this example would be for any other activity besides commerce. This is because the „Illah (missing the Juma‟ prayer) occurs due to these activities as well. Therefore, working, playing, eating etc. are prohibited in the time of Juma‟ because all of these activities prevent Muslims from performing the Juma‟ prayer.