Hii inaonyesha kwamba muda ni sharti la kusihi kwa salam. Hata hivyo, pale ambapo malipo yanafanyika papo hapo na hakuna muda uliowekwa, basi haiitwi mauzo ya mkopo wa mbele, kwa sababu kinachofanya iwe Salam na salaf ni kuleta mbele moja ya malipo na kuchelewesha lingine. Ni lazima muda ujulikane kutokana na kauli ya Mtume ﷺ: "kwa muda unaojulikana." Kubainisha muda kunahusu tu muda ambao wenyewe hautofautiani, kama mwezi, mwaka, miezi sita, au hadi tarehe fulani ambayo hakuna tofauti kubwa juu yake, kama Eid al-Adha au hadi Ramadhani. Vilevile, inaruhusiwa salam iwe hadi Pasaka ya Wakristo na mfungo wao, kwa kuwa hilo linajulikana na halitofautiani. Tofauti ndogo husamehewa. Kila muda unaruhusiwa kuchelewesha, hakuna tofauti kati ya muda wa karibu au wa mbali. Hata hivyo, neno "muda" (ajal) lina maana ambayo hufuatwa kulingana na desturi za watu kuhusu maana yake. Ikiwa wanaona kwamba saa moja haihesabiwi humo bali ni aina ya mauzo ya papo hapo, na ikiwa wanaiona kuwa muda, basi saa moja inahesabiwa kuwa muda kama vile mwaka unavyohesabiwa kuwa muda.
This indicates that the period is a condition for the validity of salam. However where it is immediate and no period is determined then it is not called advance credit sale because that which makes it Salam and salaf is the bringing forward of one of the compensations and delaying the other. It is necessary that the period be known due to the Prophet (saw)’s statement: “for a known period.” Specifying the period is only for a period which in itself does not differ such as a month, year, six months or to such and such date in a way that there is no great difference over it like Eid al-Adha or to Ramadhan. Similarly it is valid that the salam be for the Easter of the Christians and their fasting as this is known and does not differ. A minor difference is forgiven. Every period is allowed to be delayed until without difference between a nearby or a remote period. However the word “period” (ajal) has an indication which is acted upon according to the terminology of the people over its indication. If they consider that an hour is not considered therein but rather it is from the type of immediate (sale), and if they consider it a period thereupon the hour is considered a period like the year is considered a period.
Vivyo hivyo pia ni lazima bei ijulikane, kutokana na kauli yake (saw): “Basi na amlipe mapema kwa bei inayojulikana.” Haiwezekani isipokuwa bei ikabidhiwe mara moja katika kikao cha mkataba. Hivyo, ikiwa wakandarasi watatengana kabla bei yote haijapokewa, mkataba wote unabatilika. Hii ni kwa sababu mauzo ya malipo ya mapema (salaf) katika lugha ya Kiarabu ambayo Mtume wa Allah (saw) alitusemesha nayo ni kitu kinachotolewa kwa ajili ya kitu, yaani fedha hutolewa mapema kwa bidhaa inayochukuliwa baadaye. Basi mtu asipolipa kwa kile alichoagiza mapema (aslaf), basi hajalipa chochote mapema; ameahidi tu kwamba atalipa mapema. Akilipa sehemu ya bei, iwe kidogo au nyingi, basi mauzo ya mapema ni sahihi katika kile alichokabidhiwa na batili katika kile ambacho hakukabidhiwa. Muuzaji kupokea bei kutoka kwa mnunuzi ni sharti la uhalali wa Salam. Kuwepo kwa bidhaa iliyouzwa wakati wa mauzo si sharti. Salam inaruhusiwa katika kitu kilichopo na kisichopo wakati Salam inapofungwa, na kwa mtu aliye nacho na asiye nacho chochote. Hii ni kwa sababu Mtume alipofika Madina, watu walikuwa wakilipa mapema kwa matunda kwa mwaka mmoja au miwili. Inajulikana kwamba matunda hayadumu kwa kipindi hicho, na Mtume hakuwakataza kwa mwaka mmoja au miwili, bali aliwakubalia hilo. Hivyo inaruhusiwa kulipa bei ya bidhaa itakayokabidhiwa baada ya kipindi maalum kinachozingatiwa kuwa kipindi, iwe bidhaa ipo au haipo. Hata hivyo ni sharti kwamba katika bei kusiwe na udanganyifu mkubwa; bali ni wajibu bei iwe kulingana na soko wakati wa kufungwa mkataba, sawa na kipindi cha kuchelewesha, si kukabidhiwa kwa bidhaa. Hii ni kwa sababu Salam ni mauzo, na udanganyifu mkubwa umekatazwa katika mauzo yote, hivyo Salam imo ndani yake. Kama ilivyo haramu bidhaa kuchukuliwa mara moja kwa bei ya kuahirishwa kupitia udanganyifu uliopitiliza, vivyo hivyo haijuzu kuuza bidhaa itakayochukuliwa baadaye kwa bei itakayochukuliwa mara moja kupitia udanganyifu uliopitiliza. Kwa hiyo udanganyifu katika salam ni haramu. Ikiwa udanganyifu utajitokeza katika salam, basi hukumu yake ni hukumu ya udanganyifu katika mauzo; kwa aliyedanganywa kuna chaguo. Akitaka, anaweza kuvunja mauzo, na akitaka, anaweza kuyatekeleza. Si haki yake kuchukua tofauti kati ya bei ya bidhaa halisi na bei ambayo imenunuliwa nayo. Hata hivyo, chaguo hili limeanzishwa juu ya masharti mawili. La kwanza, kutokuwepo kwa ujuzi wakati wa mkataba. La pili, ziada au upungufu wa udanganyifu ambao watu hawadanganyiki nao. Udanganyifu wa wazi hupimwa kwa tathmini ya mfanyabiashara, hivyo kile wanachokiona kuwa udanganyifu hukua kuwa udanganyifu, na kile wasichokiona hakiwi udanganyifu.
Similarly it is necessary that the price be known due to his (saw) statement: “Then let him pay in advance for a known price.” It is not permitted except that the price be handed over immediately in the contract session, so if the contractors separate before the entire price is taken possession, then the whole contract is invalidated. This is because advance sale in the Arabic language with which the Messenger of Allah (saw) addressed us is something being given for something i.e.. Money is given in advance for a good taken afterwards. So if one does not pay for what he ordered in advance (aslaf) then he has not paid in advance for anything; he has merely promised that he will pay in advance. Were he to pay some of the price, whether a little or most of it, then the advance sale is valid in what he gave possession of and void in what he did not give possession of. The seller taking possession of the price from the buyer is a condition for the validity of Salam. As for the existence of the sold good during the sale, it is not a condition. Salam is permitted in what is present and what is not present when the Salam is contracted, and with the one who has something with him and the one without anything. This is because the Prophet came to Madinah; they would pay in advance for fruits for a year or two. It is known that fruits do not remain for this period and the Messenger did not prohibit them from one year or two but rather consented upon that for them. Hence it is permitted to pay the price of the good to be delivered after a specific period considered a period, whether the good exists or not. However it is a condition that there should not be in the price excessive fraud; rather it is obligatory that the price be according to the market during the sale contract similar to the deferred period, not the delivery of the good. This is because the Salam is a sale and excessive fraud is forbidden in all sales so the Salam in included within it. Just as it is haram for a good to be taken possession of immediately for a deferred price via excessive fraud, similarly it is not permitted to sell a good to be taken possession of in the future for a price to be taken possession of immediately via excessive fraud, therefore fraud in salam is haram. If fraud appears in the Salam then its rule is the rule of fraud in sale; for the deceived, there is an option. If he wishes, he can annul the sale and if he wishes he can execute it. It is not for him to take the difference between the price of the real good and the price with which it is bought. However this option is established upon two conditions. Firstly, the absence of knowledge at the time of the contract. Secondly, the deceitful surplus or deficit which the people are not deceived with. Clear fraud is evaluated by the evaluation of the trader so what they consider is fraud develops into and what they do not, is not