Overall meaning : Allah Almighty begins this noble surah with the letters yaa seen, which are among the disconnected letters with which He begins some other surahs, to establish the miraculous nature of the Qur’an, to prove the Arabs’ total inability to produce with them anything like it, even though it is composed of the very letters they speak!
Then He swears by the Qur’an, which is full of wisdom with regard to its teachings and laws, that Muhammad, may Allah bless him and grant him peace, is one of His messengers, that he is on a straight path which leads to Him, and that this Qur’an has been sent down by Allah, the All-Mighty and All-Merciful, so that Muhammad, may Allah bless him and grant him peace, may warn with it a people whose fathers had not been warned before it, and hence they are unaware of the truth.
The Almighty then says: Most of the Arab idolaters have become justly deserving of punishment for stubbornly persisting in their unbelief, and so they will never believe. We had bound their hands to their necks with shackles of iron reaching up to their chins, so that they cannot bow their heads, making it impossible for them to see; and We have set a barrier in front of them and a barrier behind them and placed a veil over their sight, so that they cannot see. It makes no difference to them, Muhammad, whether or not you warn them: they will not believe the truth you have brought them!
You can profitably warn only those who believe the Qur’an and follow its teachings and who fear Allah though they cannot see Him. To these give the good news of forgiveness and a rich reward. We will surely bring the dead back to life on Resurrection Day to repay them for their deeds. We record whatever actions they do in this worldly life as well as the traces of good and evil they leave behind after their death; and We have recorded everything in a Clear Book (The Preserved Tablet).