Possibly by extension, the number 49, the square of seven, is used in many Chinese folk, Taoist and Buddhist rituals. For example, it is believed[by whom?] that a recently deceased spirit will linger in the living world for 49 days. Therefore a second requiem ritual is often performed at the end of 49 days. Similarly, many rituals require the performer to undergo a 49-day cleansing, fasting, etc.
When named in ritualistic context, the number 49, as the square of seven, is almost always explicitly invoked as "7-7-49