What to say immediately following Witr

Subhaanal-Malikil-Quddoosi.

Glory is to the King, the Holy. [Recite three times in Arabic, and raise and extend the voice on the third time and say . . .]

رَبُّ الْمَلَائِكَةِ وَالرُّوحِ

Rabbil-malaa’ikati warroohi.

Lord of the angels and the Spirit.

Reference: An-Nasa’i

[mp3: http://www.areweprepared.ca/audio/witr.mp3]