Fortress of the Muslim (Hisn al-Muslim)
حصن المسلم
(17) Chapter: While bowing in prayer
(17) دعاء الركوع
Hisn al-Muslim 35 
Subbūḥun, Quddūsun, Rabbul-malā'ikati warrūḥ. Glory (to You) , Most Holy (are You) , Lord of the angels and the Spirit. Reference: Muslim 1/353, Abu Dawud 1/230.
سُبـّوحٌ قُـدّْوس ، رَبُّ الملائِكَـةِ وَالـرُّوح
Reference : Hisn al-Muslim 35