Allah exalted says,
ص
Saad,
We have already discussed the separate letters in the beginning of the Tafsir of Surah Al-Baqarah, and there is no need to repeat it here.
وَالْقُرْانِ ذِي الذِّكْرِ
By the Qur'an full of reminding.
means, by the Qur'an which includes all that is in it as a reminder and a benefit to people in this life and the Hereafter.
Ad-Dahhak said that the Ayah,
ذِي الذِّكْرِ
(full of reminding) is like the Ayah,
لَقَدْ أَنزَلْنَأ إِلَيْكُمْ كِتَـباً فِيهِ ذِكْرُكُمْ
Indeed, We have sent down for you (O mankind) a Book in which there is Dhikrukum. (21;10)
i.e., your reminder.
This was also the view of Qatadah and of Ibn Jarir.
Ibn Abbas, may Allah be pleased with him, Sa`id bin Jubayr, Isma`il bin Abi Khalid, Ibn Uyaynah, Abu Husayn, Abu Salih and As-Suddi said;
ذِي الذِّكْرِ
(full of reminding).
"Full of honor," i.e., of high standing.
There is no contradiction between the two views, because it is a noble Book which includes reminders and leaves no excuse and brings warnings. The reason for this oath is to be found in the Ayah;
إِن كُلٌّ إِلاَّ كَذَّبَ الرٌّسُلَ فَحَقَّ عِقَابِ
Not one of them but denied the Messengers; therefore My torment was justified. (38;14)
Qatadah said,
"The reason for it is to be found in the Ayah;
بَلِ الَّذِينَ كَفَرُوا فِي عِزَّةٍ وَشِقَاقٍ
Nay, those who disbelieve are in false pride and opposition."
This was the view favored by Ibn Jarir.
Allah exalted says,
بَلِ الَّذِينَ كَفَرُوا فِي عِزَّةٍ وَشِقَاقٍ