Invocation
Immediately after salam of the witr prayer
"سبحان الملك القدوس" ثلاث مرات والثالثة يجهر بها ويمد بها صوته "ربِّ الملائكةِ والرّوح"
Glory is to the King, the Holy. [Recite three times in Arabic, and raise and extend the voice on the third time and say...] Lord of the angels and the Spirit.
An-Nasa'i 3/244, Ad-Daraqutni and others. The final addition is from
Ad-Daraqutni's version 2/ 31 and its chain of narration is authentic. See
the checking of Zadul-Ma'ad by Shu'aib Al-Arna'ut and 'Abdul-Qadir
Al-Arna'ut 1/337.