In the biblical context, the distinction between clean and unclean birds is primarily found in the Old Testament, where dietary laws are outlined for the Israelites. These laws are part of the broader Mosaic Law, which includes various regulations on what is permissible for consumption. The primary passages that address clean and unclean birds are found in Leviticus 11 and Deuteronomy 14.

Leviticus 11:13-19 :
In Leviticus 11, God provides Moses and Aaron with a list of birds that are considered unclean and therefore not to be eaten by the Israelites. The passage states:
"These are the birds you are to detest and not eat because they are detestable: the eagle, the vulture, the black vulture, the red kite, any kind of black kite, any kind of raven, the horned owl, the screech owl, the gull, any kind of hawk, the little owl, the cormorant, the great owl, the white owl, the desert owl, the osprey, the stork, any kind of heron, the hoopoe, and the bat."

Deuteronomy 14:11-18 :
Deuteronomy reiterates the list of unclean birds, emphasizing the importance of adhering to these dietary restrictions. The passage reads:
"You may eat any clean bird, but these you may not eat: the eagle, the vulture, the black vulture, the red kite, the black kite, any kind of falcon, any kind of raven, the horned owl, the screech owl, the gull, any kind of hawk, the little owl, the great owl, the white owl, the desert owl, the osprey, the cormorant, the stork, any kind of heron, the hoopoe, and the bat."

Characteristics of Unclean Birds:
The unclean birds listed in these passages are generally birds of prey or scavengers. They are often associated with death and decay, as many of them feed on carrion. This association with death and impurity is likely a key reason for their classification as unclean. The prohibition against eating these birds serves as a symbolic reminder of the need for the Israelites to remain separate from practices considered impure or defiling.

Clean Birds:
While the Bible does not provide an exhaustive list of clean birds, it implies that birds not listed as unclean are permissible to eat. Clean birds are typically those that do not feed on carrion and are not birds of prey. They are often domesticated or commonly found in agricultural settings, such as chickens, doves, and pigeons.

Symbolism and Spiritual Significance:
The distinction between clean and unclean birds carries symbolic and spiritual significance. It reflects the broader biblical theme of holiness and separation from impurity. By adhering to these dietary laws, the Israelites were reminded of their covenant relationship with God and their call to be a holy nation. The laws served as a daily, tangible expression of their commitment to God's commandments and their identity as His chosen people.

New Testament Perspective:
In the New Testament, the dietary laws, including those concerning clean and unclean birds, are re-evaluated in light of Christ's redemptive work. In Acts 10, Peter receives a vision in which God declares all foods clean, symbolizing the inclusion of Gentiles into the covenant community. This vision marks a significant shift in the understanding of dietary laws, emphasizing the spiritual purity found in Christ rather than adherence to specific food regulations.

The distinction between clean and unclean birds, while rooted in the Old Testament, ultimately points to the broader biblical narrative of holiness, covenant, and redemption.