Allah relates what happened when Musa traveled with the Children of Israel after Fir`awn's destruction.
﴿فَأَتَوْاْ عَلَى قَوْمٍ يَعْكُفُونَ عَلَى أَصْنَامٍ لَّهُمْ قَالُواْ يَمُوسَى اجْعَلْ لَّنَآ إِلَـهًا كَمَا لَهُمْ ءَالِهَةٌ قَالَ إِنَّكُمْ قَوْمٌ تَجْهَلُونَ﴾
إِنَّ هَـؤُلآء مُتَبَّرٌ مَّا هُمْ فِيهِ وَبَـطِلٌ مَّا كَانُواْ يَعْمَلُونَ-﴾
(And they came upon a people devoted to some of idols. They said: "O Musa! Make for us god as they have gods.'' He said: "Verily, you are a people who know not. Verily, these people will be destroyed for that which they are engaged in. And all that they are doing is in vain.'') ﴿7:138-139﴾ Then, Allah made a covenant with Musa of thirty nights after which He added to them ten more nights. Thus, they were forty nights in all. The covenant was that he was to fast these number of days, during both the day and night. Thus, Musa made haste to go to the Mountain and he left his brother, Harun, in charge over the Children of Israel. This is why Allah says,
﴿وَمَآ أَعْجَلَكَ عَن قَومِكَ يمُوسَى ﴾
قَالَ هُمْ أُوْلآء عَلَى أَثَرِى﴾
("And what made you hasten from your people, O Musa'' He said: "They are close on my footsteps.'') These means that they have arrived and are settled near the Mountain.
﴿وَعَجِلْتُ إِلَيْكَ رَبِّ لِتَرْضَى﴾
(and I hastened to You, O my Lord, that You might be pleased.) meaning, "So You will be more pleased with me.''
﴿قَالَ فَإِنَّا قَدْ فَتَنَّا قَوْمَكَ مِن بَعْدِكَ وَأَضَلَّهُمُ السَّامِرِىُّ ﴾
((Allah) said: "Verily, We have tried your people in your absence, and As-Samiri has led them astray.'') Allah informs His Prophet, Musa, of what happened to the Children of Israel after he left them, and their deification of the calf that As-Samiri had made for them. During this time period, Allah wrote for Musa the Tablets, which contained the Tawrah. Allah said,
﴿وَكَتَبْنَا لَهُ فِى الاٌّلْوَاحِ مِن كُلِّ شَىْءٍ مَّوْعِظَةً وَتَفْصِيلاً لِّكُلِّ شَىْءٍ فَخُذْهَا بِقُوَّةٍ وَأْمُرْ قَوْمَكَ يَأْخُذُواْ بِأَحْسَنِهَا سَأُوْرِيكُمْ دَارَ الْفَـسِقِينَ ﴾
(And We wrote for him on the Tablets the lesson to be drawn from all things and the explanation for all things (and said): "Hold unto these with firmness, and enjoin your people to take the better therein. I shall show you the home of evildoers.'') ﴿7:145﴾ This means, "I will show you the final outcome of what will happen to those who abandon My obedience and oppose My command.'' Concerning Allah's statement,
﴿فَرَجَعَ مُوسَى إِلَى قَوْمِهِ غَضْبَـنَ أَسِفاً﴾
(Then Musa returned to his people in a state of anger and sorrow ﴿Asif﴾.) This means that after Allah informed him of what they were doing, he became extremely angry and upset with them. He was very worried for them. During this time he received the Tawrah, which contained their Shari`ah (Law), this was a great honor for them. For they were a people who used to worship other than Allah. Every person with sound reason and good sense could see that what they were doing was false and foolish. This is why Allah said that he (Musa) returned to them in a state of anger and sorrow. The word for sorrow used here is Asif, which is used to emphasize to the severity of his anger. Mujahid said, "In a state of anger and sorrow means worried.'' Qatadah and As-Suddi said, "Asif here means in a state of sadness because of what his people had done after him.''
﴿قَالَ يَقَوْمِ أَلَمْ يَعِدْكُمْ رَبُّكُمْ وَعْداً حَسَناً﴾
(He (Musa) said: "O my people! Did not your Lord promise you a fair promise...'') This means, "Did He not promise you in that which I have spoken to you, every good in this life and in the Hereafter, and the good end in the final outcome of things You have already witnessed how He helped you defeat your enemy (Fir`awn) and He made you victorious over him and He blessed you with other bounties as well through His help.''
﴿أَفَطَالَ عَلَيْكُمُ الْعَهْدُ﴾
(Did then the promise seem to you long in coming) meaning, `in waiting for what Allah had promised you and forgetting His previous favors and the covenant that He made with you before.'
﴿أَمْ أَرَدتُّمْ أَن يَحِلَّ عَلَيْكُمْ غَضَبٌ مِّن رَّبِّكُمْ﴾
(Or did you desire that wrath should descend from your Lord on you, ) The word `Or' here means `Nay, but.' It is used here to separate between a previous item and a coming item. It is as if it is saying, "Nay, but you want to make permissible the anger of your Lord upon you by what you have done. Therefore, you have broken your promise to me.'' The Children of Israel said in reply to Musa's blame and rebuke,
﴿مَآ أَخْلَفْنَا مَوْعِدَكَ بِمَلْكِنَا﴾
(We broke not our promise to you of our own will,) Meaning by our power and our choice. Then, they began making lame excuses and they told him how they got rid of that which they were carrying of Coptic jewelry that they had borrowed from them (the Egyptian Copts) when they left Egypt. Therefore they cast it, meaning that they threw it away. Thus, it became a calf that made a moaning sound that would gradually rise in pitch. This calf was an ordeal, a hindrance and test. This is why Allah said,
﴿فَكَذَلِكَ أَلْقَى السَّامِرِىُّفَأَخْرَجَ لَهُمْ عِجْلاً جَسَداً لَّهُ خُوَارٌ﴾
("...that was what As-Samiri suggested.'' Then he took out (of the fire) for them (a statue of) a calf which was mooing.) Muhammad bin Ishaq reported that Ibn `Abbas said,
﴿هَـذَآ إِلَـهُكُمْ وَإِلَـهُ مُوسَى﴾
(This is your god, and the god of Musa.) "So they became religiously devoted to it (the calf) and they loved it with a love that they had never loved anything else with before. '' Allah then says,
﴿فَنَسِىَ﴾
(but he had forgotten.) This means that he abandoned what he was following of the religion of Islam. This is referring to As-Samiri. Allah says in refuting them and rebuking them, and also explaining to them their folly and foolishness in that which they had done,
﴿أَفَلاَ يَرَوْنَ أَلاَّ يَرْجِعُ إِلَيْهِمْ قَوْلاً وَلاَ يَمْلِكُ لَهُمْ ضَرّاً وَلاَ نَفْعاً ﴾
(Did they not see that it could not return them a word (for answer), and that it had no power either to harm them or to do them good) This is about the calf. `Do they not see that it does not respond to them when they ask it and when they speak to it'
﴿وَلاَ يَمْلِكُ لَهُمْ ضَرّاً وَلاَ نَفْعاً﴾
(and that it had no power either to harm them or to do them good) Meaning in their worldly affairs and matters of the Hereafter. Ibn `Abbas said, "Nay, by Allah, the moaning sound of the calf was nothing but wind that would enter into its behind and come out of its mouth, thus causing it to make a sound.'' In a Hadith of Al-Fitun recorded from Al-Hasan Al-Basri, it is mentioned that this calf's name was Bahmut. In reference to the excuse of these ignorant people, they claimed that they were merely ridding themselves of the jewelry of the Copts. In the process of doing so, they cast the jewelry (into the pit of fire) and ended up worshipping the calf. Thus, they were seeking to rid themselves of something detestable, but wound up doing something even worse. This is similar to an authentic narration reported from `Abdullah bin `Umar. A man from `Iraq asked him about the ruling of mosquitoes' blood if it get on one's garment. The man wanted to know if it is permissible to pray in such a garment or not. Ibn `Umar replied by saying, "Look at the people of `Iraq. They killed the grandson of the Messenger of Allah , Al-Husayn, and yet they're asking about the blood of the mosquito.''
﴿وَلَقَدْ قَالَ لَهُمْ هَـرُونُ مِن قَبْلُ يقَوْمِ إِنَّمَا فُتِنتُمْ بِهِ وَإِنَّ رَبَّكُمُ الرَّحْمَـنُ فَاتَّبِعُونِى وَأَطِيعُواْ أَمْرِى - قَالُواْ لَن نَّبْرَحَ عَلَيْهِ عَـكِفِينَ حَتَّى يَرْجِعَ إِلَيْنَا مُوسَى ﴾
(90. And Harun indeed had said to them beforehand: "O my people! You are being tried in this, and verily, your Lord is (Allah) the Most Gracious, so follow me and obey my order.'') (91. They said: "We will not stop worshipping it, until Musa returns to us.'')