As long as you have vowed it, you must continue to say it

I recite Surah Sajdah and Surah Ad Dahr at night and I vowed to recite it every night except in the case if I am not well some day.but I vowed because I knew from islamqa that Surah Ad Dahr is from the Sunnah to recite at night .Recently I read another fatwa at islamqa in which Surah Mulk was given with Surah Sajdah.Which one is right and can I change from Surah Dahr to Surah Al Mulk without Kaffarat Yemen as I only intended because of the Sunnah?

Reading/Reciting the Quran |