History of surah The letter Saad

Name
Surah Sad, like the vast majority of the surahs of the Holy Qur'an Which was not mentioned in a venerable Hadith in its name, but was named according to the diligence of the Companions - may God be pleased with them - who named the Surahs to distinguish them from each other. And Surah Sad was so named because it begins with the letter S, and this is in the saying of the Almighty, " Sad [These letters (Sad etc.) are one of the miracles of the Quran and none but Allah (Alone) knows their meanings]. By the Quran full of reminding." 
This is also true of several Surahs that begin with letters of the alphabet, such as Surah Qaf and Surah Noun, and these interrupted letters are known to God Almighty and may indicate a miracle. The Noble Qur'an, which consists of these letters, and yet people are not able to find an example of it

Period of Revelation
Surah S was revealed after Abu Talib fell ill and the Messenger -peace and blessings be upon him- Quraysh came to him, as stated in the following noble hadith: To prevent this, they complained to Abu Talib, and he said: O son of my brother, what do you want from your people? He said, "Uncle, all I want from them is a word with which the Arabs the non-Arabs pay tribute." He said, "What is the word?" He said, "One word." He said, " What is it? He said, "There is no god but Allah." Then they said, "Shall I make the gods one God? He said, Then the Quran was revealed to them, " Sad. By the Qur'an containing reminder * But those who disbelieve are in pride and dissension," until he reached, " This is nothing but an invention." 
The commentators said that the Islam of Umar ibn al-Khattab - may God be pleased with him - divided the Quraish and entered  the delight of the hearts of the believers, Al-Walid bin Al-Mughirah said to the Quraysh, "Go to Abu Talib. You have missed him." They said to him, "You are our sheikh and our elder. You know what these fools have done, and we have come to you to judge between us and your nephew." So he called him to him and said to him, " O son of my brother, these are your people asking you the same thing, so do not give in to your people," he said, "And what do they ask of me?" -: "Would you tell me one word by which you would rule over the Arabs and by which the non-Arabs would be indebted to you?" Abu Jahl said, " God, your father, we will give it to you and ten times as much, and so the Prophet - God's prayer and peace be upon him - said, "Say there is no God but Allah." Then they fled from it and stood up and said, " I make the gods one God, how can the whole creation be in one God? Then God Almighty revealed these verses about them until He said, " The people of Noah denied before them, and they denied Our servant and said, "A madman," and he was repelled."

Theme and topics
The sura, like other Meccan suras, dealt with three main themes: the question of monotheism, the question of revelation to the Prophet Muhammad, may God bless him and grant him peace, and the question of reckoning in the hereafter. It began with the Quran's oath that the polytheists lied and that those who disbelieve are in pride and discord, and everything mentioned therein of the states of the disbelievers is caused by their pride and discord, and the opposite is true of the states of the believers. These are the aims of the surah in general.