Kitāb al-Ghayba > Concealed Birth of the Imam of the Time (a.s) was not an extraordinary event
Hadith #15

وكان من قصة يونس بن متى نبي الله عليه السلام مع قومه وفراره منهم حين تطاول خلافهم له واستخفـافهم بحقوقه وغيبته عنهم وعن كل أحد حتى لم يعلم أحد من الخلق مستقره وستره الله تعالى في جوف السمكة وأمسك عليه رمقه بضرب من المصلحة إلى أن انقضت تلك المدة ورده الله تعالى إلى قومه وجمع بينهم وبينه. وهذا أيضا خارج عن عادتنا وبعيد من تعارفنا،قد نطق به القرآن وأجمع عليه أهل الإسلام.

There is the story of Yunus, the son of Mata, the messenger of God, with his people and his flight from them when they disputed him for long and violating him did not concern them much. So he went into occultation from them and from everyone; so much so that no one knew where he was. God hid him in the abdomen of a fish and saved his life for expediency until that period passed and God returned him to his people and united them. This is also extraordinary and far from the ordinary events we hear, narrated by the Quran and agreed upon by all.