Alif, Lam, Meem, Ra. These are the verses of the Book; and (13:1)

Almuntakhab Fi Tafsir Alquran Alkarim

(Alef), L. (Lam), M. (Meem), R. (Raa), the Surah opens with these introductory letters from the Arabic Alphabet to draw attention to the miracle of the Quran which though written in the peoples tongue, Cannot be emulated. These are divinely discoursed verses of the Book -the Quran- distinctly indicating that all that has been revealed to you O Muhammad from Allah, your Creator, is the truth guiding into all truth, but peoples hearts dare rise defiant against Allah and most of them are unwilling to open their minds eyes or their hearts ears

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(13:1) Alif. Lam. Mim. Ra. These are the verses of the Divine Book, and that which has been sent down to you from your Lord is the very truth, but most (of your) people do not believe in this. *1

Alif, Lam, Meem, Ra. These are the verses of the Book; and meaning

*1) This is the introduction to this Surah, in which its aim and object has been enunciated in a few words. Allah has addressed the Holy Prophet to this effect: "O Prophet ! most of your people arc rejecting the teachings of the Qur'an for one reason or the other, but the fact is that what We are sending down to you is the Truth whether people believe it or not. "
After this brief introduction, the discourse deals with the main subject of the Surah, which consists of three basic things. First,. "The whole of the universe belongs to Allah alone, and none besides Him has any right to service and worship" . Second, "There is another life after this life, in which you shall have to render an account of all your actions." Third, "I am a Messenger of Allah: whatever I am presenting before you is not from myself but from Allah." As the people were rejecting these three things, these have been reiterated over and over again in various forms to remove doubts and objections from the minds of the disbelievers.
 

Alif, Lam, Meem, Ra. These are the verses of the Book; and meaning in Urdu

ا ل م ر یہ کتاب الٰہی کی آیات ہیں، اور جو کچھ تمہارے رب کی طرف سے تم پر نازل کیا گیا ہے وہ عین حق ہے، مگر (تمہاری قوم کے) اکثر لوگ مان نہیں رہے ہیں