Allah sent down the Best Speech, the Book containing allegorical repeating verses, the skins of those who fear their Lord becomes pliant with It, then their skins and hearts become soften to Remembrance of Allah, that is the Guidance of Allah, with It He guides the one whom He intends and the one whom Allah lets to stray, there is none to guide him.
The allegorical verses are the examples and similarities of the wise verses of the Lord’s Book. That is the Mouedath as explained in verse 3: 138. ‘Repeating verses’ means everything told in the verses is mentioned at least twice. In other words, the Book revealed to Messenger Muhammed is the repetition of Its opening Surah Al-Fatiha, as told in verse 15: 87. In short, the seven verses of Al-Fatiha are repeated in the other verses of the Book.
‘With It’ means with Adhikr. ‘With It, He guides the one whom He intends’ means whoever prays with his soul, ‘Oh my Lord! Increase me in knowledge,’ and then reads and hears Adhikr—the Lord’s Permission—Allah guides him. There is none to guide the one who, after receiving Adhikr—the Criterion to distinguish good and evil—does not utilize It. See explanation 4: 87; 8: 2-4; 16: 125; 42: 52.