大毘盧遮那成佛經疏 14.14

14.14

次顯露合掌。乃屈二風指頭。捻火指第三節背上。令與其二水指頭相到也。其二水指亦在中指第三節之背也。其月天印。一如梵王無異。但想有白色為異耳。

Next, make an open añjali, bend the tips of the two wind fingers to press upon the backs of the third joints of the fire fingers, causing them to meet the tips of the two water fingers. The two water fingers are also on the backs of the third joints of the middle fingers. The Candra Deva mudrā is no different from that of King Brahmā, differing only in visualizing a white color.