A mother was regarded as ceremonially unclean after childbirth for seven days; and then for thirty-three days was prohibited from entering a sanctuary or touching anything hallowed. In the case of a female infant, the length of time required for purification doubled (Lev. 12: 5).
The idea of a ‘new birth’ is used in the NT for the beginning of a life in Christ (1 Pet. 1: 3), and as a theological term called ‘regeneration’ (Titus 3: 5, AV) was associated in the Church with baptism.