Kuajiri kunajulikana kama mkataba wa manufaa kwa malipo. Mkataba huu una aina tatu:

Hiring is known as being a contract upon benefit for compensation. This contract comes in three types:

Kwanza: Aina ya mkataba unaohusu manufaa ya vitu kama kukodisha nyumba, wanyama, magari na mengineyo. Mkataba unatekelezwa kwa kutegemea manufaa ya kitu hicho.

Firstly: A type coming upon the benefits of things like hiring houses, animals, vehicles and the like. The contract is performed upon the benefit of the thing.

Pili: Aina inayohusu manufaa ya kazi kama vile uchoraji, uhandisi, ujenzi na mengineyo. Kinachofungwa mkataba ni manufaa ya kazi hiyo.

Secondly: A type coming upon the benefits of work like painting, engineering, building and the like. What is contracted upon is the benefit of the work.

Tatu: Aina inayohusu manufaa ya watu kama watumishi, wafanyakazi na wengineo. Kinachofungwa mkataba ni manufaa ya juhudi ya mtu huyo.

Thirdly: A type coming upon the benefits of persons like servants, labourers and the like. What is contracted upon is the benefit of the effort of the person.

Katika aina hizi tatu, kilichofungwa mkataba ni manufaa yaliyomo katika kila moja yao. Kwa hiyo kitu ambacho mkataba umefanyika juu yake ni manufaa. Pesa iliyotajwa ndiyo malipo ya kubadilishana kwa manufaa haya. Kwa sababu hiyo, msingi wa kukadiria ujira ni manufaa yanayotolewa na kitu hicho, kazi hiyo, au mtu huyo. Haihusiani na thamani ya kitu kilichofanyiwa kazi wala bei yake, wala na tija ya mfanyakazi kulinganisha na mwajiri, wala na kugharamia mahitaji ya mfanyakazi. Hivyo, katika kukadiria ujira hakuna nafasi ya kupandisha au kushusha kiwango cha maisha. Si sahihi kurudisha ukadiriaji wa ujira kwenye thamani ya kitu, bei yake, tija ya mfanyakazi, au kutimiza mahitaji yake; wala kupandisha au kushusha kiwango cha maisha hakuingii katika ukadiriaji wake. Ukadiriaji wake unarejea kwenye jambo moja tu, nalo ni manufaa, kwa kuwa ni manufaa kwa ajili ya malipo ya fidia. Ujira hukadiriwa kwa kipimo cha manufaa ambayo mkataba wa kuajiri umefanyika juu yake. Pale wanapotofautiana kuhusu kiasi cha ujira, hakikadiriwi kwa ushahidi na hoja, kwa kuwa ushahidi hauna nafasi hapa, kwani hauhitaji kuthibitisha ujira. Badala yake, kujua kiasi chake na ukadiriaji wake hufanywa kwa makadirio ya wataalamu wawili wa manufaa yanayohusika, na wataalamu wawili wa kukadiria fidia yake.

In these three types, what was contracted upon was the benefit in each one of them. So the thing upon which the contract occurred is the benefit. The money mentioned is the exchange for this benefit. Hence the basis upon which estimating the wage is based is the benefit given by this thing or this work or that person. It is not in relation to the value of the thing worked upon or its price nor his productivity in relation to the employee just as is not paying for the needs of the employee. Thus there does not enter the elevation of the living standard, or its lowering, in estimating it. It is not valid to return estimating the wage to the value of the thing or its price or the worker’s productivity or fulfilment of his needs; nor does raising or lowering the living standard enter into its estimation. Its estimation returns to only one thing which is the benefit since it is a benefit upon benefit for compensation. The wage is estimated according to the measure of benefit upon which the hiring contract occurred. During difference (of opinion) over the amount of wage, it is not estimated by evidence and proof as there is no role for evidence therein since it does not require proving the wage. Rather, knowing its amount and its estimation is by the estimation of two experts in the benefit over which the benefit occurs, and two experts in the estimation of its compensation.

Hii inahusu kipengele cha msingi wa ujira, yaani kipimo ambacho ujira unakadiriwa kwacho. Kwa upande wa tofauti yake, ujira hutofautiana kulingana na tofauti ya manufaa katika watu binafsi, katika kazi moja na kazi tofauti, na katika wakati na mahali. Ujira wa wafanyakazi ambao mkataba umehusu manufaa ya nafsi zao utatofautiana kulingana na juhudi wanazozitoa. Hivyo ujira hukadiriwa kuwa kiasi fulani kwa mwenye nguvu na kiasi fulani kwa mwenye udhaifu; na kiasi fulani cha ujira kwa idadi fulani ya saa za kazi. Kwa saa nyingi zaidi hulipwa malipo makubwa zaidi, na kwa saa chache zaidi hulipwa malipo madogo zaidi, na kadhalika. Ukadiriaji wa ujira wa kazi moja ambayo mkataba wa kuajiri umefanyika juu yake hutegemea manufaa ya kazi hiyo kwa kiasi maalumu, na utatofautiana baina ya watu wanaofanya kazi hiyo kulingana na tofauti ya ujuzi wao ndani yake, kama wahandisi kwa mfano. Hivyo mhandisi atapewa ujira maalumu, nao utatofautiana baina ya wahandisi kwa tofauti ya ujuzi. Vivyo hivyo ni ukadiriaji wa ujira wa kazi tofauti kulingana na manufaa yaliyokusudiwa ndani yake wakati wa kuajiri wanaofanya kazi humo, yaani wazalishaji. Ujira wa kazi hizi utatofautiana kwa tofauti ya manufaa yake katika jamii, hivyo ujira wa mhandisi utakuwa kiasi fulani, ujira wa mjenzi kiasi fulani, na kadhalika. Ukadiriaji wa ujira wa watu katika kazi moja au kazi tofauti katika nyakati tofauti hukadiriwa kwa namna tofauti katika nyakati tofauti. Kwa mfano, mfanyakazi wa usiku hupewa zaidi ya mfanyakazi anayefanya kazi wakati wa mchana katika kazi hiyo hiyo. Vivyo hivyo, ukadiriaji wa ujira wa watu hufanyika, kwa kazi moja na kwa kazi tofauti, kwa namna tofauti mahali pamoja kuliko mahali pengine. Kwa mfano, mfanyakazi jangwani hupewa zaidi ya mfanyakazi anayefanya kazi hiyo hiyo mjini, na kadhalika. Na inaruhusiwa kukadiria ujira kwa muda maalumu wa muda mfupi, kama kwa saa, kwa siku, kwa mwezi na kwa mwaka.

This is in relation to the aspect of the basis of the wage, or in other words the unit upon which estimating the wage occurs. As for the aspect of its difference, it differs according to difference of the benefit in persons and in one job and different jobs, and in the time and place, The wage of workers over whom the contract came over the benefits of their persons will differ according to the effort which they expend, so the wage is estimated as so much for the strong and so much for the weak; and so much wage for so many hours of work. For more hours a higher pay and for lesser hours, lesser pay and so on. The estimation of wage for one job over which the contract of hiring was formed based on the the benefit of work by a specific amount, and it will differ between the persons who perform this work according to the difference of their expertise therein like engineers for example. So the engineer will be given a particular wage, and it will differ between engineers by the difference of the expertise. Similarly is the estimation of the wage for different jobs according to the benefit intended therein during the hiring of those working therein i.e. the producers. The wage for these jobs will differ by the difference of their benefit in the society so the engineer’s wage will be a particular amount, the builder’s wage a particular amount and so on. The estimation of the wage of the people in one job or different jobs at different times is estimated differently at different times. For example, the worker at night is given more than the worker working during daytime in the same job. Similarly the estimation of the wage for people takes place, for one job and for different jobs differently on one place than in another place. For example the worker in the desert is given more than the worker doing the same job in the city and so on. And it is permitted to estimate the wage temporarily by a specific time like hourly, daily, monthly and annually.