Is it permissible for me to read Riyad al-Salihin during my menstrual period?

It is permissible for a menstruating woman to touch books of Tafsir (exegesis) and Hadith, such as Riyadh al-Salihin, and anything that contains Quranic verses but is not referred to as a Mus'haf (complete copy of the Quran); this is because the Prophet, peace and blessings be upon him, wrote a verse from the Quran in a letter to Heraclius.