The answer
Some people say that the preparation week was originally called the week of Heraclius. This is an inaccurate testimony since the historical timeline of that week of fast is by far older than the time of Emperor Heraclius. St. Severus of Antioch (513 AD) in his 18th homily, about 120 years before Heraclius, says that the Holy Great Fast is eight weeks. The number 8 refers to renewal. The 5 days of total abstinence each week symbolize purification of the 5 senses. Thus, the fast achieves its purpose which is the renewal of the senses.Egeria, a woman, widely regarded to be the author of a detailed account of a pilgrimage to the Holy Land about 384-386 AD had given a detailed account of the liturgical services including the Holy Week. In her writings, she did mention the one week fast as having been initiated towards the end of the fourth century. The historical origin of that week of fast has been traced and confirmed through research and studies. Our Coptic Orthodox church has retained this tradition since then.
Answered by His Eminence Metropolitan Youssef (opens in a new tab)