This is a blessed Book, We have sent it down confirming that which has been before it
Sura Al-A'nam
(92) وَ هذا كِتابٌ أَنْزَلْناهُ مُبارَكٌ مُصَدِّقُ الَّذِي بَيْنَ يَدَيْهِ وَ لِتُنْذِرَ أُمَّ الْقُرى وَ مَنْ حَوْلَها وَ الَّذِينَ يُؤْمِنُونَ بِالْآخِرَةِ يُؤْمِنُونَ بِهِ وَ هُمْ عَلى صَلاتِهِمْ يُحافِظُونَ
92. " And this is a blessed Book, We have sent it down confirming that which has been before it, and that you may warn (the people of) the Mother City (Mecca) and those around her; and those who believe in the Hereafter believe in it, and they are careful of their prayers."
Commentary :
The objective meaning of the phrase 'a blessed Book', mentioned in the verse, is 'the Qur'an' which is the source of many benefits and interests. Among them is that its recitation is good, practising its content causes good things to come forth; it contains the first and the last sciences; the ordinances of lawful and unlawful things are found in it. As long as the world exists and religious obligations are enjoined, the Qur'an will exist and will never be abrogated. The verse says :
" And this is a blessed Book, We have sent it down ..."
Not only this Book is the source of all kinds of goodnesses, blessings, and triumphs, but also it confirms all the Books which were sent down before it.
"... confirming that which has been before it, ..."
The purpose of the statement saying that the Qur'an confirms the sacred Books before it is that all the divine signs that have been referred to in those Books adopt to it.
Therefore, both from the point of content, and from the point of evidences and historical documents, the signs of rightfulness are seen in the Qur'an.
Then, the verse explains the purpose of sending the Qur'an down as follows :
"... and that you may warn (the people of) the Mother City (Mecca) and those around her; ..."
Mecca has been called ' 'Umm-ul-Qura ' because, as it is said, she is the origin of the beginning genesis of the whole lands all over the earth. There are many Islamic traditions which denote that the existing dry lands throughout the world expanded from the ground beneath the Ka'bah which in Islamic literature have been recorded by the name of /dahw-ul-'ard/ (Expantion of the Earth). Thus, the Qur'anic phrase 'and those around her' encompasses all the people throughout of the world.
Then, at the end of the verse, the Qur'an says :
"... and those who believe in the Hereafter believe in it, and they are careful of their prayers."
The Importance of Prayer !
Amongst all the religious ordinances only prayer is referred to in the above-mentioned verse. So, as we know, prayer is the symbol of the link and connection between the believing servants and Allah (s.w.t.); and, for this very reason, it is the most important worship comparing all other godly worships.
Some commentators believe that when this verse was revealed the only religious obligation had been prayer.
source : http://www.maaref-foundation.com