With these three, King David praised the Daughter of the King (Malkhut). It is this that is written: (Ps. 121:1) A song La-Ma’alot (of) degrees... Lamed ל (=30) degrees (ma)’alot there are, specifically, – there are thirty levels, through which Daughter ascends towards Father.
With five strings of the harp – which are the ‘five mentions’ of the Name, with which Y”Y is mentioned five times in this Psalm 121: one is my help is from Y”Y (ibid.), 2 is may Y”Y guard you, 3 is Y”Y is your shade, 4 is may Y”Y protect you from all evil, 5 is may Y”Y guard your going out and your coming in.