Vignana Bhairava Tantra - 84

Look at the empty sky

Aakasham Vimalam Pashyan Krithwa Drishtim Nirantaram|

Sthabdhathma Tatkshanath Devi Bhairavim Vapurapnuyath||

By going on looking into the pure sky for a long period of time, the consciousness becomes one with the sky and attains to the body of Bhairava which is nothing but the empty space. - SS

Vignana Bhairava Tantra - 79

Meditate on the space within a circle

Upavishyasane Samyak Baahu Krithwardha Kunchithau|

Kakshavyomni Manah Kurvan Shamamaayati Tallayath||

By sitting in the correct posture of keeping the body, neck and head centred and in a straight line, stretching the arms out to form a circle, focus on the circular space formed by the hands. The mind merges in this formation and attains to peace. - Swahilya Shambhavi (Pic. Chaturagiri.)