Definition and Context:
The term "abominable customs" refers to practices and behaviors that are considered detestable and offensive in the sight of God, as outlined in the Bible. These customs are often associated with idolatry, immorality, and other actions that violate the commandments and statutes given by God to the Israelites. The Bible frequently warns against adopting such customs, especially those practiced by surrounding nations, as they lead to spiritual corruption and separation from God.

Biblical References:

1. Leviticus 18:30 :
"You must keep My charge not to practice any of the abominable customs that were practiced before you, so that you do not defile yourselves by them. I am the LORD your God."
· This verse is part of a larger passage where God instructs the Israelites on maintaining holiness by avoiding the detestable practices of the nations they are displacing. The chapter lists various sexual sins and other behaviors considered abominable.

2. Deuteronomy 18:9-12 :
"When you enter the land that the LORD your God is giving you, do not imitate the detestable ways of the nations there. Let no one be found among you who sacrifices his son or daughter in the fire, practices divination or sorcery, interprets omens, engages in witchcraft, casts spells, or consults a medium or spiritist, or inquires of the dead. For whoever does these things is detestable to the LORD, and because of these detestable practices the LORD your God will drive out the nations before you."
· This passage highlights specific practices considered abominable, emphasizing the importance of remaining distinct from the pagan nations and their idolatrous customs.

3. 2 Kings 16:3 :
"Instead, he walked in the way of the kings of Israel and even sacrificed his son in the fire, according to the abominations of the nations that the LORD had driven out before the Israelites."
· This verse refers to King Ahaz of Judah, who adopted the abominable customs of the surrounding nations, including child sacrifice, which was strictly forbidden by God.

4. 2 Chronicles 28:3 :
"Moreover, Ahaz burned sacrifices in the Valley of Ben Hinnom and sacrificed his sons in the fire, according to the abominations of the nations that the LORD had driven out before the Israelites."
· Similar to the account in 2 Kings, this verse underscores the severity of adopting abominable customs, which led to the moral and spiritual decline of the nation.

5. Ezekiel 11:12 :
"And you will know that I am the LORD, for you have not walked in My statutes or kept My ordinances, but have conformed to the customs of the nations around you."
· The prophet Ezekiel condemns the Israelites for abandoning God's laws in favor of the abominable customs of their neighbors, leading to their judgment and exile.

Theological Significance:
Abominable customs are a recurring theme in the Bible, serving as a warning against the dangers of syncretism and the loss of spiritual identity. The Israelites were called to be a holy nation, set apart for God, and were repeatedly admonished to avoid the corrupt practices of other nations. These customs are often linked to idolatry, which is seen as a direct affront to the sovereignty and holiness of God. The biblical narrative consistently portrays the adoption of such customs as leading to divine judgment and the eventual downfall of those who engage in them.