It is narrated from Hazrat Aisha (may Allah be pleased with her) that sometimes the Prophet (peace and blessings be upon him) would fast so continuously that we would say, "Now the Prophet (peace and blessings be upon him) will keep fasting continuously," and sometimes he would leave off fasting so much that we would say, "Now the Prophet (peace and blessings be upon him) will keep leaving off fasting continuously." And the Prophet (peace and blessings be upon him) used to recite Surah Bani Isra'il and Surah Az-Zumar every night.
Hadith Referenceمسند احمد / مسند النساء / 24388
Hadith Gradingحکم دارالسلام:حديث صحيح دون قوله: وكان يقرأ فى كل ليلة ... وهذا إسناد فيه أبو لبابة فيه كلام