攝大毘盧遮那成佛神變加持經入蓮華胎藏海會悲生曼荼攞廣大念誦儀軌供養方便會 2.66

2.66

Next, jihvā is explained: based on the previous Tathāgata-Armor, the spaces press the nails of the two waters;
this is the jihvā touch mudrā, and touch [the body] while reciting the mantra.
For the Speech-Door, join the hollowed palms, bend and pinch the winds and waters together,
bend both spaces slightly, and make the earths and fires form a peak.
Alternatively, it is said: bend the earths and waters, make the winds and fires form a peak, and open both spaces to touch them.
There are five mudrās and four mantras.