The Minor, Trivial Biblical Stuff, Part 6: The Horns of the Altar

In 1 Kings 1:50-52 and 2:28-34, we read that (NKJV):

Now Adonijah was afraid of Solomon; so he arose, and went and took hold of the horns of the altar. And it was told Solomon, saying, "Indeed Adonijah is afraid of King Solomon; for look, he has taken hold of the horns of the altar, saying, ‘Let King Solomon swear to me today that he will not put his servant to death with the sword.’" Then Solomon said, "If he proves himself a worthy man, not one hair of him shall fall to the earth; but if wickedness is found in him, he shall die." So King Solomon sent them to bring him down from the altar. And he came and fell down before King Solomon; and Solomon said to him, "Go to your house."

Then news came to Joab, for Joab had defected to Adonijah, though he had not defected to Absalom. So Joab fled to the tabernacle of the LORD, and took hold of the horns of the altar. And King Solomon was told, "Joab has fled to the tabernacle of the LORD; there he is , by the altar." Then Solomon sent Benaiah the son of Jehoiada, saying, "Go, strike him down."

Some horned altars from Iron Age II (10th-6th centuries BC) Ekron. 

So Benaiah went to the tabernacle of the LORD, and said to him, "Thus says the king, ‘Come out!’" And he said, "No, but I will die here." And Benaiah brought back word to the king, saying, "Thus said Joab, and thus he answered me." Then the king said to him, "Do as he has said, and strike him down and bury him, that you may take away from me and from the house of my father the innocent blood which Joab shed. So the LORD will return his blood on his head, because he struck down two men more righteous and better than he, and killed them with the sword––Abner the son of Ner, the commander of the army of Israel, and Amasa the son of Jether, the commander of the army of Judah––though my father David did not know it. Their blood shall therefore return upon the head of Joab and upon the head of his descendants forever. But upon David and his descendants, upon his house and his throne, there shall be peace forever from the LORD." So Benaiah the son of Jehoiada went up and struck and killed him; and he was buried in his own house in the wilderness.

An altar from the temple complex at Tel Dan.

Ever wondered what these horns are? The International Standard Bible Encyclopedia defines the horns of the altar as:

Projections at each of the four corners of the altar of burnt offering (Ex. 27:2; 38:2; Ezk. 43:15) and of the altar of incense (Ex. 30:2f.; 37:25f.). In both cases they were to be of one piece with the altar. Blood was smeared on the horns of the altar of burnt offering for the consecration of Aaron and his sons (Ex. 29:12), in the sin offering for a ruler (Heb. nasi'), and on the Day of Atonement (Lev. 16:18). The horns of the altar of incense were smeared with blood in the case of sin offerings for the high priest and the congregation of Israel (Lev. 4:17,18). Fugitives seeking asylum would cling to the horns, thus putting themselves under the divine protection (cf. 1 K. 1:50-53; 2:28; an addition to the LXX [2:29] reads, "I fled to the Lord"), though not in the case of wilful murder (1 K. 2:31-34; cf. Ex. 21:14); the horns appear to epitomize the holiness of the altar. The cutting off of the horns in Am. 3:14 signifies the removal of Israel's last refuge from God's judgment.

As was noted, in Exodus 27:1-2 and 30:1-3, God commands Moses (NKJV):

You shall make an altar of acacia wood, five cubits long and five cubits wide—the altar shall be square—and its height shall be three cubits. You shall make its horns on its four corners; its horns shall be of one piece with it. And you shall overlay it with bronze...

You shall make an altar to burn incense on; you shall make it of acacia wood. A cubit shall be its length and a cubit its width—it shall be square—and two cubits shall be its height. Its horns shall be of one piece with it. And you shall overlay its top, its sides all around, and its horns with pure gold; and you shall make for it a molding of gold all around...

An altar at Beersheba, probably connected to a temple or cult center
 in the city. When Tel Be'er-Sheva was first excavated,
archeologists discovered sandstone blocks in the walls of storehouses
 - most of the blocks used in the ancient city was made of
 limestone. They eventually took these blocks and
 reconstructed the altar, as shown here. It is thought that the altar was
dismantled during the reforms of King Hezekiah in circa 8th century BC.

In Ancient Near Eastern culture, altars were thought of to be the god's 'table' or even as a representation or even a symbol of the deity himself (cf. Psalms 26:6-7; 43:4; 118:27). Now, it was actually unclear what the horns' - to which an extreme degree of holiness were attached - exact origins are and the exact symbolism and purposethey had in Ancient Near Eastern societies. We can infer that some altars had their horns used to latch the sacrificial animals on, but it seems to not be a universal practice. Some have interpreted these horns as being descendants of matztzevot ("standing stones") which were originally placed in the altar but was gradually moved farther into the corners as time passed. Others interpret them more mundanely as serving a more practical purpose: as censer-holders.

Later, these horns were interpreted as symbols of the concepts of strength and protection that are present in the word "horns" (qeren); hence the reason why Adonijah and Uriah clutched the projections of the holy altar: they are seeking the protection of the Lord for themselves - and the Semitic idea that one 'contracts' holiness and impurity by touching either a holy or impure person or item. Also note that many deities throughout the ancient Near East were either portrayed with horns or are associated with horned animals, such as bulls, perhaps as a symbol of virility and strength. Jeremiah meanwhile denied the horns expiatory power as they too are infected with the sin that is engraved on the heard (Jer. 17:1). And as mentioned in the ISBE quote above, cutting off the horns (Amos 3:14) apparently made an altar useless and unfit, signifying "the removal of Israel's last refuge from God's judgment".