All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is not an obligation to recite those Ath-kaar continuously in order to gain the virtue that is mentioned for reciting them; rather, if one recites them at different times of the day, he will obtain their reward, Allah willing, as stated by the scholars but it is better to recite them continuously.
An-Nawawi said in his commentary on the Hadeeth of the Prophet “Whoever says a hundred times in a day, 'La Ilaaha Illa Allah Wahdahu La Shareeka Lahu, Lahul Mulk Wa Lahul Hamd Wa huwa 'ala Kulli Shay'in Qadeer'; the apparent meaning of the Hadeeth is that one gets the reward mentioned in this Hadeeth if he says this Thikr one hundred times, whether he recited it in succession or not in succession at different times, or some of it at the beginning of the day and some of it towards the end of the day, but it is better if he says it in succession at the beginning of the day so that it will be a protection for him during the entire day.” [End of quote]
Al-Mubaarak Poori said in explaining the Hadeeth: “Whoever says Subhaan Allah wa bihamdih (Glorify be to Allah and praise be to Him) one hundred times, he said: His saying ‘Subhaan Allah wa bihamdih’ means in a day one hundred times as in the narration by Al-Bukhaari and Muslim; At-Taybi said: Whether they were recited at different times or continually in one council (meeting) or at different councils at the beginning of the day or at the end of the day, but it is more appropriate to recite them altogether at the beginning of the day.” [End of quote]
The same thing applies to the recitation of Soorah al-Kahf on Friday; the view that we adopt here at Islamweb is that the apparent meaning of the Ahadeeth does not require to recite the entire Surah at once; rather, if one recites it during different parts of the day, then he has achieved what is commanded regarding it. What is meant is that the entire Surah should be recited on Friday. Also, if one recites it while praying, then it is acceptable, because what is meant is that one gets the reward by reciting it. Nonetheless, taking the initiative to recite it entirely and not to delay its recitation is more appropriate as a way of hastening to perform good deeds and in compliance with the Saying of Allah (which means): {… so race to [all that is] good.} [Quran 5:42] Al-Qurtubi said: {so race to [all that is] good.}; means race to acts of obedience.
For more benefit, please refer to Fatwa 362701.
Allah knows best.