Ijara — ijaradan foydalanish nimadan iborat bo‘lsa, ishchiga nisbatan ijara uning mehnatidan foydalanishdir. Ishchini yollashda ish turini, ish muddatini, ish haqini va sarflanadigan mehnatni belgilash zarur. Ish noma’lum bo‘lib qolmasligi uchun uni aniq belgilash kerak, chunki noma’lum ishga asoslangan yollash fosid (yaroqsiz) hisoblanadi. Shuningdek, ish muddatini belgilash kerak, masalan, kunlik, oylik yoki yillik. Xuddi shunday, ishchining ish haqi ham aniq belgilanishi lozim. Ibn Mas’ud rivoyat qilgan: Payg‘ambar ﷺ aytdilar: “Agar sizlardan biringiz ishchi yollasa, uning ish haqini unga ma’lum qilsin.” Shuningdek, ishchi sarflashi kerak bo‘lgan mehnatni ham belgilash zarur. Shunga ko‘ra, ishchidan uning imkониyatidan tashqari ishni talab qilish joiz emas. Alloh (SWT) aytadi:

Hiring involves utilising the benefit of the hired thing. With regard to the worker, hiring is utilising his effort. It is necessary in hiring a worker, to define the work, the period of work, the wage and the effort. The work has to be defined so as not to become unknown, because hiring based on unknown work is invalid (Fasid). It is also necessary to define the period of work, such as daily, monthly or yearly. Similarly, the wage of the worker has to be defined. Ibn Mas’oud said: The Prophet (pbuh) (pbuh) said: “If any one of you employed a worker then He has to inform Him of his wage.” It is also necessary to define the effort that the worker has to expend. Accordingly it is not allowed to demand of the worker work that is beyond his capacity. Allah (swt) said:

"Alloh hech kimga o'z imkoniyatidan tashqari yuk yuklamaydi." [Al-Baqara: 286],

“Allah burdens not a person beyond his scope.” [Al-Baqarah: 286],

Пайғамбар (с.а.в.) айтдилар: «Агар мен сизларга бирон нарсани буюрсам, уни имкониятингиз борича бажаринг», — деб Бухорий ва Муслим Абу Хурайрадан ривоят қилганлар. Ишчига фақат унинг одатдаги имконияти доирасидаги меҳнатни юклаш мумкин. Меҳнатни ўлчайдиган ҳақиқий тарози бўлмагани учун, ҳар куни иш соатларини белгилаш энг мумкин бўлган яхши ўлчов ҳисобланади. Бундан ташқари, ишнинг турини ҳам аниқлаш керак, масалан, қаттиқ ёки юмшоқ тупроқни қазиш, металл қуйиш ёки тош кесиш. Бу ҳам меҳнат миқдорини белгилайди. Шундай қилиб, иш унинг турини, давомийлигини, ҳақини ва унга сарфланган меҳнатни кўрсатиш орқали аниқланади. Шариат ишчини ёллашга рухсат берганда, унинг ишини тури, давомийлиги, ҳақи ва меҳнати бўйича белгилаш қоидаларини белгилаб қўйган. Ишчи ўз ишини бажаргани эвазига оладиган ҳақ, унинг сарфлаган меҳнати натижасида вужудга келган мулкидир.

The Prophet (pbuh) (pbuh) said: “If I commanded you of something, do of it as much as you can”, as narrated by Bukhari and Muslim from Abu Hurairah. The worker should not be asked to undertake effort except that which is within his ordinary capacity. As a real scale cannot measure effort, defining the number of working hours every day is the best possible measure. In addition the type of work has to be defined as well, such as digging hard or soft soil, forging a metal or cutting stones. This also determines the amount of effort. The work would have thus been defined by stating its type, duration, wage and the effort spent in it.When Shar’a allowed employing a worker, it laid out provision for defining his work in terms of the type, duration, wage and effort. The wage received by the worker, in return for his execution of the work, is the property He accrued as a result of the effort He spent.