( وَكَذَٰلِكَ يَجْتَبِيكَ رَبُّكَ…) (And thus will your Lord choose you…): That is to say, Allah (swt) will choose, confer His Favour upon Yusuf (PBUH).
(… وَيُعَلِّمُكَ مِن تَأْوِيلِ الْأَحَادِيثِ…) (… teach you the interpretation of narratives…): That is, Allah (swt) will teach you the interpretation of dreams. This will become clear from the context of the story, particularly, when Yusuf (PBUH) interpreted dreams in prison. Ya’qub (PBUH) knew through his prophethood that Allah (swt) would grant Yusuf (PBUH) the understanding and interpretation of dreams. This teaching would come directly from Allah (swt) Himself, as it was a Divine instruction.
(… وَيُتِمُّ نِعْمَتَهُ عَلَيْكَ…) (… and complete His favor upon you…): It means the completeness of blessings, indicating that the gift is connected between this world and the Hereafter. This is how blessings are perfected. If a blessing is only in this worldly life and not connected to the blessings of the Hereafter, then it is an incomplete blessing.
(… وَعَلَىٰ آلِ يَعْقُوبَ…) (… and upon the family of Jacob…): Despite the plots of Yusuf’s brothers, as we will see; in the end, goodness and blessings will encompass the family of Ya’qub (PBUH). In other words, Divine mercy, gifts, and the divine message will be fulfilled upon Yusuf (PBUH) and upon the family of Ya’qub (PBUH).
(… كَمَا أَتَمَّهَا عَلَىٰ أَبَوَيْكَ مِن قَبْلُ إِبْرَاهِيمَ وَإِسْحَاقَ…) (… and upon the family of Jacob…): Ishaq (PBUH) is Yusuf’s grandfather, and Ibrahim (PBUH) is his grandfather’s father. The Prophet Muhammad (saws) described Prophet Yusuf (PBUH) as follows:
“The honorable, the son of the honorable the son of the honorable, i.e. Joseph, the son of Jacob, the son of Isaac, the son of Abraham.”[1]
Yusuf (PBUH), son of Ya’qub, son of Ishaq, son of Ibrahim (PBUT).
(... إِنَّ رَبَّكَ عَلِيمٌ حَكِيمٌ ) (… Indeed, your Lord is Knowing and Wise):
This addresses Yusuf (PBUH) not to rush the matters, as there is wisdom in everything that will happen to you. This is the meaning Ya’qub (PBUH) conveyed to young Yusuf when he narrated the dream to him. Then the Quran unfolds the scene of Yusuf’s brothers and the complete story associated with it:
[1] Sahih al-Bukhari: Book of Commentary on the Qur’an, Chapter of Tafsir Surah Yusuf, Hadith No. 4411.