"He has no partner. And of this I have been commanded, and I am the first of the Muslims."
Islam is the Religion of all Prophets
The Ayah,
وَأَنَاْ أَوَّلُ الْمُسْلِمِينَ
(and I am the first of the Muslims), means,
from this Ummah, according to Qatadah.
This is a sound meaning, because all Prophets before our Prophet were calling to Islam, which commands worshipping Allah alone without partners.
Allah said in another Ayah,
وَمَأ أَرْسَلْنَا مِن قَبْلِكَ مِن رَّسُولٍ إِلاَّ نُوحِى إِلَيْهِ أَنَّهُ لا إِلَـهَ إِلاَّ أَنَاْ فَاعْبُدُونِ
And We did not send any Messenger before you but We revealed to him (saying): "None has the right to be worshipped but I, so worship Me." (21:25)
Allah informed us that Nuh said to his people,
فَإِن تَوَلَّيْتُمْ فَمَا سَأَلْتُكُمْ مِّنْ أَجْرٍ إِنْ أَجْرِىَ إِلاَّ عَلَى اللَّهِ وَأُمِرْتُ أَنْ أَكُونَ مِنَ الْمُسْلِمِينَ
But if you turn away, then no reward have I asked of you, my reward is only from Allah, and I have been commanded to be of the Muslims. (10:72)
Allah said,
وَمَن يَرْغَبُ عَن مِّلَّةِ إِبْرَهِيمَ إِلاَّ مَن سَفِهَ نَفْسَهُ وَلَقَدِ اصْطَفَيْنَـهُ فِي الدُّنْيَا وَإِنَّهُ فِى الاٌّخِرَةِ لَمِنَ الصَّـلِحِينَ
إِذْ قَالَ لَهُ رَبُّهُ أَسْلِمْ قَالَ أَسْلَمْتُ لِرَبِّ الْعَـلَمِينَ
وَوَصَّى بِهَأ إِبْرَهِيمُ بَنِيهِ وَيَعْقُوبُ يَـبَنِىَّ إِنَّ اللَّهَ اصْطَفَى لَكُمُ الدِّينَ فَلَ تَمُوتُنَّ إَلاَّ وَأَنتُم مُّسْلِمُونَ
And who turns away from the religion of Ibrahim except him who deludes himself Truly, We chose him in this world and verily, in the Hereafter he will be among the righteous.
When his Lord said to him, "Submit (i.e. be a Muslim)!"
He said, "I have submitted myself (as a Muslim) to the Lord of the all that exists."
And this was enjoined by Ibrahim upon his sons and by Yaqub (saying), "O my sons! Allah has chosen for you the (true) religion, then die not except as Muslims." (2:130-132)
Yusuf, peace be upon him, said,
رَبِّ قَدْ اتَيْتَنِى مِنَ الْمُلْكِ وَعَلَّمْتَنِى مِن تَأْوِيلِ الاٌّحَادِيثِ فَاطِرَ السَّمَـوَتِ وَالاٌّرْضِ أَنتَ وَلِىِّ فِى الدُّنُيَا وَالاٌّخِرَةِ تَوَفَّنِى مُسْلِمًا وَأَلْحِقْنِى بِالصَّـلِحِينَ
My Lord! You have indeed bestowed on me of the sovereignty, and taught me something of the interpretation of dreams -- the (Only) Creator of the heavens and the earth! You are my Wali (Protector) in this world and in the Hereafter. Cause me to die as a Muslim, and join me with the righteous. (12:101)
Musa said,
وَقَالَ مُوسَى يقَوْمِ إِن كُنتُمْ ءامَنْتُمْ بِاللَّهِ فَعَلَيْهِ تَوَكَّلُواْ إِن كُنْتُم مُّسْلِمِينَ
فَقَالُواْ عَلَى اللَّهِ تَوَكَّلْنَا رَبَّنَا لاَ تَجْعَلْنَا فِتْنَةً لِّلْقَوْمِ الظَّـلِمِينَ
وَنَجِّنَا بِرَحْمَتِكَ مِنَ الْقَوْمِ الْكَـفِرِينَ
And Musa said: "O my people! If you have believed in Allah, then put your trust in Him if you are Muslims."
They said: "In Allah we put our trust. Our Lord! Make us not a trial for the folk who are wrongdoers. And save us by your mercy from the disbelieving folk." (10:84-86)
Allah said,
إِنَّأ أَنزَلْنَا التَّوْرَاةَ فِيهَا هُدًى وَنُورٌ يَحْكُمُ بِهَا النَّبِيُّونَ الَّذِينَ أَسْلَمُواْ لِلَّذِينَ هَادُواْ وَالرَّبَّانِيُّونَ وَالاٌّحْبَارُ
Verily, We did send down the Tawrah, therein was guidance and light, by which the Prophets, who submitted themselves to Allah's will, judged for the Jews. And the rabbis and the priests (did also). (5:44)
and,
وَإِذْ أَوْحَيْتُ إِلَى الْحَوَارِيِّينَ أَنْ ءَامِنُواْ بِى وَبِرَسُولِى قَالُواْ ءَامَنَّا وَاشْهَدْ بِأَنَّنَا مُسْلِمُونَ
And when I (Allah) inspired Al-Hawariyyun (the disciples) (of Isa) to believe in Me and My Messenger, they said: "We believe. And bear witness that we are Muslims." (5:111)
Therefore, Allah states that He sent all His Messengers with the religion of Islam, although their respective laws differed from each other, and some of them abrogated others. Later on, the Law sent with Muhammad abrogated all previous laws and nothing will ever abrogate it, forever. Certainly, Muhammad's Law will always be apparent and its flags raised high, until the Day of Resurrection.
The Prophet said,
نَحْنُ مَعَاشِرُ الاَْنْبِيَاءِ أَوْلاَدُ عَلَّتٍ دِينُنَا وَاحِد
We, the Prophets, are half brothers, but our religion is one.
Half brothers, mentioned in the Hadith, refers to the brothers to one father, but different mothers. Therefore, the religion, representing the one father, is one; worshipping Allah alone without partners, even though the laws which are like the different mothers in this parable, are different. Allah the Most High knows best.
Imam Ahmad recorded that Ali said that when the Messenger of Allah used to start the prayer with Takbir (saying, "Allahu Akbar" (Allah is the Great)) he would then supplicate,
وَجَّهْتُ وَجْهِيَ لِلَّذِي فَطَرَ السَّمَوَاتِ وَالاَْرْضَ حَنِيفًا وَمَا أَنَا مِنَ الْمُشْرِكِينَ إِنَّ صَلَتِي وَنُسُكِي وَمَحْيَايَ وَمَمَاتِي للهِ رَبِّ الْعَالَمِين
I have directed my face towards He Who has created the heavens and earth, Hanifan and I am not among the Mushrikin. Certainly, my prayer, sacrifice, living and dying are all for Allah, Lord of the worlds.
اللَّهُمَّ أَنْتَ الْمَلِكُ لاَ إِلَهَ إِلاَّ أَنْتَ أَنْتَ رَبِّي وَأَنَا عَبْدُكَ ظَلَمْتُ نَفْسِي وَاعْتَرَفْتُ بِذَنْبِي فَاغْفِرْ لِي ذُنُوبِي جَمِيعًا لاَ يَغْفِرُ الذُّنُوبَ إِلاَّ أَنْتَ وَاهْدِنِي لاَِحْسَنِ الاَْخْلَقِ لاَ يَهْدِي لاَِحْسَنِهَا إِلاَّ أَنْتَ وَاصْرِفْ عَنِّي سَيِّيَهَا لاَ يَصْرِفُ عَنِّي سَيِّيَهَا إِلاَّ أَنْتَ تَبَارَكْتَ وَتَعَالَيْتَ أَسْتَغْفِرُكَ وَأَتُوبُ إِلَيْك
O Allah! You are the King, there is no deity worthy of worship except You. You are my Lord and I am Your servant. I have committed wrong against myself and admitted to my error, so forgive me all my sins. Verily, You, only You forgive the sins. (O Allah!) Direct me to the best conduct, for none except You directs to the best conduct. Divert me from the worst conduct, for only You divert from the worst conduct. Glorified and Exalted You are. I seek Your forgiveness and repent to You.
This Hadith, which was also recorded by Muslim in the Sahih, continues and mentions the Prophet's supplication in his bowing, prostrating and final sitting positions.
