Origen

Literally, hereby is signified the quickness of the Divine foresight, which reaches even to the least things. But mystically, the five sparrows justly represent the spiritual senses, which have perception of high and heavenly things: beholding God, hearing the Divine voice, tasting of the bread of life, smelling the perfume of Christ’s anointing, handling the Word of Life. And these being sold for two farthings, that is, being lightly esteemed by those who count as perishing whatever is of the Spirit, are not forgotten before God. But God is said to be forgetful of some because of their iniquities.