With their spiritual eyes, Gyeong-seok and Gong-u saw spirits requesting an audience with Sangjenim do the embracing-heaven-and-caressing-earth bow four times. Sangjenim responded by bringing his hands together in front of his forehead.
Dojeon 4:90:5

Before daily mediation or a chiseong, practitioners do sabaesimgo, which means "four bows and a prayer." The style of bowing is bancheonmuji (embracing heaven and caressing earth). This special bow, made in reverence to Sangjenim, Taemonim, and other spirits, signifies uniting the virtue of heaven, earth, and humanity. According to Korean tradition, this bow was performed by the king or a specially appointed person in making an offering to heaven. The bow originated in the ancient practice of singyo (spirit teaching). After doing four bancheonmuji bows, the meditator does another bow called buboksimgo in which there is a moment of silence and personal prayer.

   Another simple bow called eupbae, in which practitioners brings their hands together in front of their foreheads, is performed at various times, such as when entering or leaving the dojang, before and after placing something on an altar, and when opening and closing a chiseong.