And [he was told], "Throw down your staff." But when he saw it writhing as if it was a snake, he turned in flight and did not return. [Allāh said], "O Moses, approach and fear not. Indeed, you are of the secure.
Musa's Return to Egypt and how he was honored with the Mission and Miracles on the Way
In the explanation of the previous Ayah, we have already seen that Musa completed the longer and better of the two terms, which may also be understood from the Ayah where Allah says:
فَلَمَّا قَضَى مُوسَى الاٌّجَلَ
(Then, when Musa had fulfilled the term,) meaning, the longer of the two; and Allah knows best.
وَسَارَ بِأَهْلِهِ
(and was traveling with his family,) They said: "Musa missed his country and his relatives, so he resolved to visit them in secret, without Fir`awn and his people knowing. So he gathered up his family and the flocks which his father-in-law had given to him, and set out on a cold, dark, rainy night. They stopped to camp, and whenever he tried to start a fire, he did not succeed. He was surprised by this, and while he was in this state,
نُودِيَ مِن شَاطِئِ الْوَادِ الْأَيْمَنِ فِي الْبُقْعَةِ الْمُبَارَكَةِ مِنَ الشَّجَرَةِ أَن يَا مُوسَىٰ إِنِّي أَنَا اللَّـهُ رَبُّ الْعَالَمِينَ He was called by a voice coming from a side of the right valley in the blessed ground, from the tree, saying" 0 Musa, I am Allah, the Lord of the worlds" - 28:30). This subject was also mentioned in Surahs Taha and An-Naml in the story of Musa (علیہ السلام) . In Surah Taha it is said إِنِّي أَنَا رَبُّكَ (it is Me your Lord - 20:12) and in Surah An-Naml نُودِيَ أَن بُورِكَ مَن فِي النَّارِ (So when he came to it, he was called: "Blessed is the one who is in the fire - 27:8), while in the present Surah (Al-Qasas) it appears as إِنِّي أَنَا اللَّـهُ رَبُّ الْعَالَمِينَ (I am Allah the Lord of the worlds - 28:30). Although the wordings are slightly different here, yet the meanings are almost the same. The incident is related in the words which suited to the situation being described. (کَذا قال الامام). The refulgence that Sayyidna Masa (علیہ السلام) had seen in the form of fire was only in the form of an example (mithali), because it is impossible for a worldly being to see the actual refulgence of Allah Ta` ala. Masa (علیہ السلام) is called لَن تَرَانِي (7:143) (You will never see Me) in respect of actual refulgence.
That day, the girls returned home earlier than usual. When their father asked the reason, they told him that a traveller had arranged for their cattle to be watered early. The girl’s father asked them why they had not brought him home so that he could partake of their meal. So, one of the girls went back to the well and brought Moses along with her. It took only a few days to show that Moses was hard working as well as honest. So, the old gentleman, agreeing with his daughter’s opinion, kept Moses in his service permanently. The fact is that, honesty and hard work embrace all the necessary qualities. If any candidate has to be chosen, there is no better standard than these two qualities by which to judge him. At a later stage, the old gentleman gave one of his daughters in marriage to Moses. However, as he was in dire need of a young man to look after his household and property, he made Moses agree to reside with him for eight years or ten years, thereafter he could go anywhere he liked.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.