10 The adversaries of the LORD shall be broken to pieces; out of heaven shall he thunder upon them: the LORD shall judge the ends of the earth; and he shall give strength unto his king, and exalt the horn of his anointed. (1Sam. 2:10) 

and exalt the horn of his anointed - Hebrew: וְיָרֵם קֶרֶן מְשִׁיחוֹ (v'yarem keren Meshicho)

 

The word "keren" is translted too so: strength, rays of light (Hebrew Lexicon of Strong). 

 

"Exalt the horn of his anointed" means that Messiah will come in His strength (power) and glory, the world will see the light of Messiah, the light of the King of Kings.    

 

"... and so the Targum paraphrases the words, ``he shall give strength to his king and enlarge the kingdom of his Messiah.'' With which Kimchi agrees, and says, the thing is doubled or repeated, for the King is the Messiah; and to him the words are applied by other Jewish writers (F16), ancient and modern." (John Gill http://www.biblestudytools.com/commentaries/gills-exposition-of-the-bible/1-samuel-2-10.html)

3 The God of my rock; in him will I trust: he is my shield, and the horn of my salvation, my high tower, and my refuge, my saviour; thou savest me from violence. (2Sam. 22:3)

2 The LORD is my rock, and my fortress, and my deliverer; my God, my strength, in whom I will trust; my buckler, and the horn of my salvation, and my high tower. (Psalms 18:2)

67 And his father Zacharias was filled with the Holy Ghost, and prophesied, saying,
68 Blessed be the Lord God of Israel; for he hath visited and redeemed his people,
69 And hath raised up an horn of salvation for us in the house of his servant David; (Luke 1:67-69) 

69  A horn - "Signifies honour, plenty, and strength. A horn of salvation - That is, a glorious and mighty Saviour." (Wesley's Notes http://www.bible-center.ru/comments/wesley_eng/lu/1)