What types of allusions does Anderson use to depict her father's secrecy about his traumatic war experiences?

Anderson uses a variety of Biblical allusions in order to depict the secrecy surrounding her father's wartime experiences. After Anderson states that her father was unable to talk to her about his traumatic war experiences for 40 years, she makes two Biblical references in order to illustrate her point. Anderson states that within her father's long period of silence, there was "one year of silence for every day of the Flood,/one year for every day from Lent until Easter" (7).