الْحَمْدُ لِلَّهِ الَّذِي خَلَقَ السَّمَاوَاتِ وَالْأَرْضَ وَجَعَلَ الظُّلُمَاتِ وَالنُّورَ ثُمَّ الَّذِينَ كَفَرُوا بِرَبِّهِمْ يَعْدِلُونَ ﴿۱﴾ هُوَ الَّذِي خَلَقَكُمْ مِنْ طِينٍ ثُمَّ قَضَى أَجَلًا وَأَجَلٌ مُسَمًّى عِنْدَهُ ثُمَّ أَنْتُمْ تَمْتَرُونَ ﴿۲﴾

﴾1﴿ Alhamdu lillaahil lazee khalaqas samaawaati wal arda wa ja'alaz zulumaati wannoor; summal lazeena kafaroo bi Rabbihim ya'diloon
﴾2﴿ Huwal lazee khalaqakum min teenin summa qadaaa ajalanw wa ajalum musamman 'indahoo summa antum tamtaroon

﴾1﴿ All the divine attributes belong exclusively to Allah—the One who created the heavens and the earth and brought forth darkness and light. Yet, the disbelievers still set up others as equals to their Lord.
﴾2﴿ It is Allah alone—He is the One who created you from clay, then determined a term (for your death), and there is another fixed term (for all creation) known only to Allah. Yet still, you doubt.

Relevancy: The connection between Surah Al-An‘am and the previous Surah is that in the previous Surah, there was encouragement to fulfill covenants—especially those related to what is lawful and unlawful—and a refutation of the polytheism of the Christians. In this Surah, the main objective, which is the Oneness of Allah (Tawhid), is explained in detail with proofs.
Claim of this surah: It is to establish the Oneness of Allah (Tawhid) with rational and scriptural proofs, and to refute all forms of polytheism and all types of polytheists, along with providing the method of instruction.
Summary of the surah: In this Surah, there are two main sections. The first section extends up to verse 117 and contains a refutation of doctrinal polytheism. Within this, there are six sub-sections. The first sub-section is up to verse 11, where the claim of Tawhid (Oneness of Allah) is made, and for that, there are three rational proofs, each containing three points. After that, there are three types of warnings, followed by three types of worldly threats, then answers to three questions, and finally, three types of consolations at the end.

[1] In this (section), Tawhid (Oneness of Allah) is established first with a rational proof, which is of three kinds: relating to the higher realms, the lower realms, and the intermediary. “Darkness and light” here is general—it can refer to things perceptible, like night and day, or abstract, like polytheism and monotheism, ignorance and knowledge. “Then those who disbelieve in their Lord...” is a warning to the deniers, and “then” (thumma) is either for mentioning something after or for expressing astonishment. “They set up equals” (ya‘diloon) comes from ‘adl, meaning equality; here, it means they equate other creations with their Lord—that is, they commit shirk (polytheism). Or, it comes from ‘adl in the sense of turning away, so it could mean “they turn away” from the truth. “Darknesses” (zulumaat) is mentioned in plural because there are many causes, types, and forms of darkness, but “light” is singular because true guidance is one.
[2] This is the second rational proof. The meaning of "ajal" (first term) is death, and the meaning of the second "ajal" is the time of resurrection (the Day of Judgment). In this, there are three points: “from clay” (min teen)—this is the original and primary substance of all humans; or it means that your father (Adam) was created from clay. In the word “teen,” there is an indication that within humans there is the capacity for knowledge and perfection through struggle, just as useful things are made from clay with effort. “He determined a term” (qadā ajalan)—this refers to the period from birth to death; “another fixed term” (wa ajalun musamman)—this refers to the time from death to resurrection, according to one view. Another view is that the first term is the actual time of death, and the second is the Day of Judgment—and this is the preferred opinion. “You still doubt” (tamtarūn) is taken from “mirya,” meaning doubt, or from “mirāʼ,” meaning dispute. The word “thumma” (then) here is to express astonishment.