This Surah is one of the earliest Surahs revealed at Makkah and it talks about 

1. Tawhid: Allah is Almighty, always glorify Him.
2. Allah has taken the responsibility off of Holy Prophet's memorization of the Qur'an by assuring him that he will not forget any portion of it.
3. Those who heed Allah's reminders will be successful in the Hereafter. 

When P (saw) was asked about favourite Sura, he said Ala. It was very close to him.  Ala is one of the names of Allah – it is one of 4 suwer of the Quran which bear one of the names of Allah swt – Rahman, Fatir, Ala and Ghafir, (which is also called Surat Momin)

Sura Ala is also one of the 6 glorification sura which begin with the Tasbeeh of Allah swt: Hadid – 57 Hashr – 59 Saff – 61 Jummah – 62 Taghabun – 63 Ala – 87. These Suras mention various Names of Allah s..tw , and Suratul Hadeed mentions 4 Names, Al Awwal ul Aakhir, Az Zahir Al Batin, The First, the Last, the Open and the Hidden, which Masters have called the Source Names, as all other attributes of Allah s..wt are necessary offshoots or derivatives from this Essential Reality.

Sayyid Qutb says that this sura turns the whole universe into a temple of glorification where the four corners echo the glory and subhan of Allah and when we were listening to the Sura, it’s rhythm, and the ending vowels of each aya seem to echo the tasbih of Al Alaa This Sura is like a capsule summary of the essence of the entire spiritual path.