The danger of depending solely on created beings

وَقَالَ لِلَّذِى ظَنَّ أَنَّهُۥ نَاجٍ مِّنْهُمَا ٱذْكُرْنِى عِندَ رَبِّكَ فَأَنسَىٰهُ ٱلشَّيْطَـٰنُ ذِكْرَ رَبِّهِۦ فَلَبِثَ فِى ٱلسِّجْنِ بِضْعَ سِنِينَ

And he said to the one whom he knew would go free, "Mention me before your master." But Satan made him forget the mention [to] his master, and he [i.e., Joseph] remained in prison several years.