Thanks to my friend Terence Wong, now I know something more about the small red envelope he sent me...
The name for the red envelope or packet is Hóng Bão, Ang Pao or Lai See (紅包 in traditional Chinese).
The ritual of exchanging red envelopes has its roots in traditional Chinese folklore and culture. The color red symbolizes good fortune and power and is used for celebrations to convey blessings and positive energy and to diffuse negative energy. Its rectangular shape resembles that of ancient shields and symbolizes protection. During the Chinese New Year celebration children are gifted with money in red envelopes. To receive money in a red envelope is considered to be lucky for the person who gives it and for the person who receives it.
The person who receives the “remedy” places the money or check in a red envelope and gives it to the Feng Shui practitioner. This exchange creates an auspicious bond between the practitioner and the client. Using the red envelope shows the recipient’s sincere intention and respect for the knowledge shared at a consultation and protects the client and practitioner as well as the teachings and ancient traditions. Use of the red envelope also strengthens and enhances the effectiveness of Feng Shui information.
Each night the Feng Shui practitioner places all the red envelopes under his/her pillow and sleeps on them, offering blessings and reinforcing the positive intentions to all those who shared in the Feng Shui experience. In the morning the practitioner removes the money and saves all red envelopes to be burned on an auspicious day.
To know more about please follow the link at Wiki: