大日經持誦次第儀軌 1.83

1.83

次當周遍身，被服金剛鎧，
身語之密印，前已依法說。
次佉字具點，以置於頂上，
思惟此真言，諸法如虛空。

Next, one should cover the entire body, / Wearing the vajra armor; / The secret mudrās of body and speech / Have already been taught in accordance with the Dharma. / Next, take the syllable KHA with its dot (bindu) / And place it upon the crown of the head, / Contemplating this mantra: / All dharmas are like empty space.