Birds are first delivered from their mothers' wombs in the form of eggs.
By breaking through the shells, they are delivered for a second time. Finally when they become full fledglings, endowed with feathers and wings, they are delivered from their nests and can fly wherever they please.
Similar is the case of meditators. They are first delivered from the distractions of the mind which have
accompanied them throughout the beginningless saṃsāra (cycle of rebirth),
through successfully setting up mindful body contemplation (mindfulness of the body kayānupassanā), or by accomplishing the work of tranquillity meditation.
Secondly, when they attain insight (vipassana) into body, mind, aggregates (rupa, nama, khandha) and so on, they are free from coarse forms of ignorance.
Finally, when the seven factors of enlightenment (bojjhaṅga), develop and mature, they become fully fledged by attaining the knowledge of the supramundane path (lokuttara-magga- ñana) called sambodhi.
Thus are they delivered from the state of worldlings (puthujjana), attaining the state of Noble Ones (ariya) the supramundane (lokkuttara): nibbāna.
The Requisites of Enlightenment (Bodhipakkhiya Dipani).
Venerable Ledi Sayadaw