Reference: al-Fawaa.id al-Jaliyyah min Duroos ash-Shaykh Ibn Baaz al-‘Ilmiyyah – Page 33
at-Tahleel (the saying of “Laa ilaaha il-Allaah”) is better than at-Tasbeeh (the saying of “Subhaa-nAllaah”) because of the statement of the Prophet ﷺ:
«Eemaan is 70-odd parts, and the highest part is the saying of “Laa ilaaha il-Allaah”», [the authenticity of this hadeeth is agreed upon by both al-Bukhaaree and Muslim]
