Taberî explains this expression in the context of the brothers asking Yûsuf to send their other brother along with them; since the brother is included in the group, the measurement/provision taken for him is the same as the measurement taken for all of them. According to him, there is no difference between reporting the news in the singular form for him or in the plural form for all of them, because the intended meaning is already understood.

فهو إذن اكتال لنفسه واكتالوا هم لأنفسهم، فقد دخل الأخ في عددهم، فسواء كان الخبر بذلك عن خاصة نفسه، أو عن جميعهم بلفظ الجميع، إذ كان مفهوما معنى الكلام وما أريد به

According to this exegete, the reading differences in the word 'yaktalu/naktalu' serve to support two different views mentioned earlier in the verse; Hamza and Kisâî's reading with ya strengthens the first view, while other qurrâ's reading with nun strengthens the second view.

قرأ حمزة والكسائي : { * يكتل } بالياء ، والباقون بالنون ، والقراءة الأولى تقوى القول الأول ، والقراءة الثانية تقوي القول الثاني

Kurtubî addresses the reading difference of 'naktali/yaktali' in this verse; he explains that the original form of the word is 'naktâlu', that the vowel is dropped due to jazm, and that the alif is dropped because of the consecutive sukûn. He transmits that the reading with nun (naktali) was preferred by Abû Ubayd because it makes the brother one of everyone included in the measure/bushel, and in the reading with ya, he transmits the claim that this would be specific only to the brother. By also citing Nahhas's objection to this, he indicates that even if read with ya, the meaning through qadîm-takhîr or through the phrase 'lâ kaylu lakum' in context will still encompass everyone.

وقراءة أهل الحرمين وأبي عمرو وعاصم نكتل بالنون وقرأ سائر الكوفيين يكتل بالياء والأول اختيار أبي عبيد ليكونوا كلهم داخلين فيمن يكتال

According to Ibn Kesîr, Yusuf's brothers informed their father that if he does not send Benjamin with them, they will receive no grain after this, but if he sends him, they will be able to obtain provisions and promised to protect him. The text also transmits a reading difference regarding the verb 'naktali'; in some readings, this verb is read with the letter ya as 'yaktali', in which case the subject of the verb becomes Benjamin himself.

يعنون بعد هذه المرة إن لم ترسل معنا أخانا بنيامين لا نكتل فأرسله معنا نكتل وإنا له لحافظون قرأ بعضهم بالياء أي يكتل هو

According to Beydâvî, the brothers returned to their father and informed him that the measure of grain was being withheld from them, and that this withholding would continue as long as they did not take Benjamin, and that if they took him, the measure would be given. Jacob, on the other hand, reminded them that they had previously given the same assurance regarding Yusuf but had failed to protect him, and stated that the true protector is only Allah, that he relied on Him and entrusted the matter to Him, and that he hoped Allah's mercy would protect him from experiencing two calamities together.

قال هل آمنكم عليه إلا كما أمنتكم على أخيه من قبل وقد قلتم في يوسف: وإنا له لحافظون. فالله خير حافظا فأتوكل عليه وأفوض أمري إليه

According to Zemahşerî, this expression reminds of Yusuf's words; it means 'if you do not bring him, then there is no measure', that is, the lifting of the measure prohibition and providing of grain as much as needed is intended. Furthermore, according to a reading variant where 'naktali' is read as 'yaktali', the meaning is also given as the measure received by his brothers being added to his own measure receipt, or his arrival being the cause of receiving the measure.

نرفع المانع من الكيل ، ونكتل من الطعام ما نحتاج إليه