This Surah has been separated from the one that preceded it in the primary Mushaf (the original copy of `Uthman) .
They (the Companions) wrote "In the Name of Allah, the Most Gracious, the Most Merciful'' on the line (i.e., the space) between these two Surahs. They did this even though this Surah is directly related to the one which precedes it, as Muhammad bin Ishaq and `Abdur-Rahman bin Zayd bin Aslam have both clarified. This is because the meaning of both of them is,
"We have prevented the Elephant from entering Makkah and We have destroyed its people in order to gather (Ilaf) the Quraysh, which means to unite them and bring them together safely in their city.''
It has also been said that the meaning of this (Ilaf) is what they would gather during their journey in the winter to Yemen and in the summer to Ash-Sham through trade and other than that. Then they would return to their city in safety during their journeys due to the respect that the people had for them because they were the residents of Allah's sanctuary. Therefore, whoever knew them would honor them. Even those who came to them and traveled with them, would be safe because of them. This was their situation during their journeys and travels during their winter and summer. In reference to their living in the city, then it is as Allah said,
أَوَلَمْ يَرَوْاْ أَنَّا جَعَلْنَا حَرَماً ءامِناً وَيُتَخَطَّفُ النَّاسُ مِنْ حَوْلِهِمْ
Have they not seen that We have made it a secure sanctuary, while men are being snatched away from all around them. (29:67).
Thus, Allah says,
For the Ilaf of the Quraysh. Their Ilaf,
This is a subject that has been transferred from the first sentence in order to give it more explanation.
Thus, Allah says,
Their Ilaf caravans, in winter and in summer.
Ibn Jarir said,
"The correct opinion is that the letter Lam is a prefix that shows amazement. It is as though He (Allah) is saying,
`You should be amazed at the uniting (or taming) of the Quraysh and My favor upon them in that.'''
He went on to say,
"This is due to the consensus of the Muslims that they are two separate and independent Surahs.''
Then Allah directs them to be grateful for this magnificent favor in His saying,
So, let them worship the Lord of this House.
meaning, then let them single Him out for worship, just as He has given them a safe sanctuary and a Sacred House.
This is as Allah says,
إِنَّمَآ أُمِرْتُ أَنْ أَعْبُدَ رَبِّ هَذِهِ الْبَلْدَةِ الَّذِى حَرَّمَهَا وَلَهُ كُلُّ شَىءٍ وَأُمِرْتُ أَنْ أَكُونَ مِنَ الْمُسْلِمِينَ
I have been commanded only to worship the Lord of this city, Who has sanctified it and to Whom belongs everything. And I am commanded to be from among the Muslims. (27:91)
Then Allah says,
Who has fed them against hunger,
meaning, He is the Lord of the House and He is the One Who feeds them against hunger.
... وَآمَنَهُم مِّنْ خَوْفٍ ﴿٤﴾
And has made them safe from fear.
meaning, He favors them with safety and gentleness, so they should single Him out for worship alone, without any partner. They should not worship any idol, rival or statue besides Him. Therefore, whoever accepts this command, Allah will give him safety in both this life and the Hereafter. However, whoever disobeys Him, He will remove both of them from him.
This is as Allah says,
وَضَرَبَ اللَّهُ مَثَلاً قَرْيَةً كَانَتْ ءَامِنَةً مُّطْمَئِنَّةً يَأْتِيهَا رِزْقُهَا رَغَدًا مِّن كُلِّ مَكَانٍ فَكَفَرَتْ بِأَنْعُمِ اللَّهِ فَأَذَاقَهَا اللَّهُ لِبَاسَ الْجُوعِ وَالْخَوْفِ بِمَا كَانُواْ يَصْنَعُونَ -
وَلَقَدْ جَآءَهُمْ رَسُولٌ مِّنْهُمْ فَكَذَّبُوهُ فَأَخَذَهُمُ الْعَذَابُ وَهُمْ ظَـلِمُونَ
And Allah puts forward the example of a township, that dwelt secure and well-content: its provision coming to it in abundance from every place, but it denied the favors of Allah. So, Allah made it taste extreme of hunger and fear, because of that which they used to do.
And verily, there had come unto them a Messenger from among themselves, but they denied him, so the torment overtook them while they were wrongdoers. (16:112-113)
This is the end of the Tafsir of Surah Quraysh, and all praise and thanks are due to Allah.