Several spontaneous practices have become characteristic of Pentecostal worship. Being "slain in the Spirit" or "falling under the power" is a form of prostration in which a person falls backwards, as if fainting, while being prayed over. It is at times accompanied by glossolalic prayer; at other times, the person is silent. It is believed by Pentecostals to be caused by "an overwhelming experience of the presence of God", and Pentecostals sometimes receive the baptism in the Holy Spirit in this posture. Another spontaneous practice is "dancing in the Spirit". This is when a person leaves their seat "spontaneously 'dancing' with eyes closed without bumping into nearby persons or objects". It is explained as the worshipper becoming "so enraptured with God's presence that the Spirit takes control of physical motions as well as the spiritual and emotional being". Pentecostals derive biblical precedent for dancing in worship from 2 Samuel 6, where David danced before the Lord. A similar occurrence is often called "running the aisles". The "Jericho march" (inspired by Book of Joshua 6:1–27) is a celebratory practice occurring at times of high enthusiasm. Members of a congregation began to spontaneously leave their seats and walk in the aisles inviting other members as they go. Eventually, a full column is formed around the perimeter of the meeting space as worshipers march with singing and loud shouts of praise and jubilation. Another spontaneous manifestation found in some Pentecostal churches is holy laughter, in which worshippers uncontrollably laugh. In some Pentecostal churches, these spontaneous expressions are primarily found in revival meetings or special prayer meetings, being rare or non-existent in the main services.