Surah Al-Hawaariyyeen, also known as Surah As-Saff is one of the purely Madinan surahs, and it has been known by this name since the time of Prophethood.
Imam Ahmad narrated from Abdullah ibn Salaam, who said: "We discussed among ourselves: 'Who among us will go to the Messenger of Allah peace and blessings be upon him and ask him about the deeds most beloved to Allah?' None of us stood up, so the Messenger of Allah peace and blessings be upon him sent someone to gather us. He recited to us this surah, meaning the entire Surah As-Saff."
Al-Imam Al-Alusi said: "It is also called 'The Surah of the Disciples' (Surah Al-Hawaariyyeen) and "The Surah of Jesus peace be upon him, (Surah Isah).
It consists of fourteen verses, and its revelation came after Surah Al-Taghaabun and before Surah Al-Fath.
The surah begins by glorifying Allah, the Exalted and Most High, above everything unworthy of Him, then directs a call to the believers, forbidding them from saying things they do not act upon:
يَا أَيُّهَا الَّذِينَ آمَنُوا لِمَ تَقُولُونَ مَا لَا تَفْعَلُونَ. كَبُرَ مَقْتًا عِندَ اللَّهِ أَنْ تَقُولُوا مَا لَا تَفْعَلُونَ.
After mentioning part of what Musa peace be upon him said to his people and what Isah peace be upon him said to his people, it follows by highlighting the nature of disbelievers: their lies against the truth and their dislike of the emergence of its light. Allah says:
وَمَنْ أَظْلَمُ مِمَّنِ افْتَرَى عَلَى اللَّهِ الْكَذِبَ وَهُوَ يُدْعَى إِلَى الْإِسْلَامِ وَاللَّهُ لَا يَهْدِي الْقَوْمَ الظَّالِمِينَ. يُرِيدُونَ لِيُطْفِئُوا نُورَ اللَّهِ بِأَفْوَاهِهِمْ وَاللَّهُ مُتِمُّ نُورِهِ وَلَوْ كَرِهَ الْكَافِرُونَ.
Then Allah directs another call to the believers, urging them, in the most eloquent manner, to strive in His path with their lives and wealth. He encourages them to emulate the disciples (of Jesus) and says:
يَا أَيُّهَا الَّذِينَ آمَنُوا كُونُوا أَنْصَارَ اللَّهِ كَمَا قَالَ عِيسَى ابْنُ مَرْيَمَ لِلْحَوَارِيِّينَ مَنْ أَنْصَارِي إِلَى اللَّهِ. قَالَ الْحَوَارِيُّونَ نَحْنُ أَنْصَارُ اللَّهِ. فَآمَنَتْ طَائِفَةٌ مِنْ بَنِي إِسْرَائِيلَ وَكَفَرَتْ طَائِفَةٌ فَأَيَّدْنَا الَّذِينَ آمَنُوا عَلَى عَدُوِّهِمْ فَأَصْبَحُوا ظَاهِرِينَ.
Thus, this noble surah begins with glorifying Allah, the Exalted and Most High, above any deficiency, forbidding words that contradict actions, and giving glad tidings to those who strive in His cause of His love and pleasure. It condemns those who harmed Allah's messengers, denying their prophethood after they had come with clear evidence. It also guides to the profitable trade that leads to ultimate success.
We ask Allah to make us all among those with whom He is pleased, and who are pleased with Him. And may Allah send blessings and peace upon our master Muhammad, his family, and all of his companions.
Surah As-Saff, like Surahs Al-Hadid and Al-Hashr before it, begins with the glorification of Allah above all that is unworthy of Him.
That is, everything in the heavens and the earth glorifies and sanctifies Allah, Exalted is He. He is the Azeez (the All-Mighty), whom no one can overpower, and the Hakim (the All-Wise) in all His words and actions.