Encountering the heavenly realm is an overwhelming experience that can easily push a person beyond their physical limits. The sheer closeness to an angel and the sudden divine revelation cast a heavy terror upon Daniel, causing him to completely lose his senses. Even though he does not hear the voice of God directly, and despite the angel speaking to him in an attempt to offer help, the overwhelming weight of the angelic presence forces him to collapse and faint [יוסף אבן יחיא, ביאור שטיינזלץ].
This reaction is not a normal state of rest. Rather, it is a deep, paralyzing trance brought on by intense fear, shock, and desolation [רש״י, מצודת דוד, מצודת ציון]. In this helpless state, Daniel falls completely flat, remaining motionless with his face pressed firmly against the earth [מצודת דוד].
Because spoken words alone are not enough to break through this intense shock and wake him, a physical intervention becomes necessary. The angel reaches out and touches him, acting exactly as a person would touch a friend to gently rouse them from a deep sleep [מצודת דוד, יוסף אבן יחיא]. This physical contact, combined with words of encouragement, infuses Daniel with renewed strength [מצודת דוד, ביאור שטיינזלץ]. It allows him to rise and stand firmly back on his feet, returning to the exact position he held at the very beginning of the vision [רש״י, מצודת דוד].