Vijnana Bhairava Tantra · Dharana 56 · Verse 79
Arms arched, mind in the armpits
Sit comfortably and bend both arms, lifting them a little away from the body, or, as some teachers instruct, raising them overhead in an arch, so that the armpits open. Place attention in the hollow of each armpit and keep it there. The posture is only a reminder, so that the mind does not wander away from those two spaces. If the arms tire, rest them and begin again. The meditation is the pair of hollows, not the shape of the arms.
Older line
Seated well, with the arms half bent, rest the mind in the hollows beneath them. As it dissolves there, peace comes.