According to Taberî, when Jacob told Joseph not to tell his dream to his brothers, he indicated that if he did tell them, his brothers would become jealous of him, set traps for him, and harbor enmity toward him, and in this way they would obey Satan. Jacob made this warning based on having previously noticed signs of jealousy directed at Joseph from among his brothers.

نزل يعقوب الشام، فكان همه يوسف وأخاه، فحسده إخوته لما رأوا حب أبيه له، ورأى يوسف في المنام كأن أحد عشر كوكبا والشمس والقمر رآهم له ساجدين، فحدث بها أباه

Kurtubî explains the warning regarding the brothers being able to plot against Joseph ('يحتالوا في هلاكك'), and then emphasizes that the dream is an honorable state and a high station, listing various hadith narrations (from sections 46, 70, 40, 49, 50, 26, 44) regarding the fact that the dream is a portion of prophethood. He clarifies that these different numbers do not contradict one another, explaining that the proximity of one's dream to prophethood changes according to the degree of one's piety, sincerity, and certainty; the dream of a truthful and God-fearing person is closer to prophethood (40 parts), while the dream of a person of moderate status corresponds to a degree between 40-70 parts.

فمن كان من أهل إسباغ الوضوء في السبرات والصبر في الله على المكروهات وانتظار الصلاة بعد الصلاة فرؤياه الصالحة إن شاء الله جزء من أربعين جزءا من النبوة ومن كانت حاله في ذاته بين ذلك فرؤياه الصادقة بين جزأين ما بين الأربعين إلى الستين لا تنقص عن سبعين وتزيد على الأربعين

Ibn Kesîr explains Jacob's advice to Joseph not to tell his brothers about his dream as stemming from fear that his brothers would set traps for him. He supports this view with hadith narrations stating that unpleasant things seen in dreams should not be told to others and that dreams do not come to pass unless they are interpreted, and he also mentions the narration regarding the necessity of concealing blessings as evidence for this context.

أي يحتالوا لك حيلة يردونك فيها ولهذا ثبتت السنة عن رسول الله صلى الله عليه وسلم قال إذا رأى أحدكم ما يحب فليحدث به وإذا رأى ما يكره فليتحول إلى جنبه الآخر وليتفل عن يساره ثلاثا وليستعذ بالله من شرها ولا يحدث بها أحدا فانها لن تضره

According to Beydâvî, Jacob told his son Joseph not to tell his brothers about his dream; because, as the dream indicated, he sensed that God would choose Joseph and make him superior to his brothers, and for this reason he feared their jealousy and injustice. Furthermore, he enters into a linguistic and rational/philosophical analysis by explaining the difference between dream (رؤيا) and sight (رؤية), stating that the imagined vision occurring in sleep is an imprint formed through the relationship between the soul and the realm of the unseen. Finally, he states that Satan is an open enemy to mankind, and just as he did to Adam and Eve, he will try to incite the brothers and provoke jealousy in them to make them set traps for Joseph.

فهم يعقوب عليه السلام من رؤياه أن الله يصطفيه لرسالته ويفوقه على إخوته، فخاف عليه حسدهم وبغيهم

According to this exegete, the verb 'kaydûke' is in the accusative case with the proviso 'an', and the meaning is 'if you tell them this, they will set traps for you.' Since the brothers' attempt at this plot is attributed to Satan, Jacob's counsel was referring to the interpretation of the dream.

والمعنى إن قصصتها عليهم كادوك