釋氏要覽 2.7

2.7

若此方之叉手也○法苑云。若指合其掌不合者。良由心慢而情散故也。必須指掌相著。不令虛也。

This corresponds to crossing the hands in this land. ○ The Fayuan [zhulin] states: If the fingers are joined but the palms are not joined, it is truly because the mind is haughty and the sentiments scattered. One must make the fingers and palms touch one another, leaving no void.