Telling Phrases - "Look up and lengthen"

Yoga Class is patterned around known phrases which guide us through the exercises. They are more or less detailed as to how much they actually describe about the relevant pose. Instead they connect to the pose through association. Here I think the alliteration and the two part patterning are crucial in the shaping of the phrase. Interestingly I have had classes with four different yoga tutors in Johnson City who all use this patterning, although it is not the formal title of a posture. I wonder if there is a patient zero teacher somewhere or whether it is simply a rhytmic description of a movement which it is easy to land upon.