And Zadok the priest took a horn of oil out of the tabernacle, and anointed Solomon. And they blew the trumpet; and all the people said, God save king Solomon.
Read Chapter 1
Cyril of Jerusalem
AD 386
You must know that this chrism is prefigured in the Old Testament. When Moses, conferring on his brother the divine appointment, was ordering him high priest, he anointed him after he had bathed in water, and thenceforward he was called “christ” [anointed], clearly after the figurative chrism. Again, the high priest, when installing Solomon as king, anointed him after he had bathed in Gihon. But what was done to them in figure was done to you, not in figure but in truth, because your salvation began from him who was anointed by the Holy Spirit in truth. Christ is the beginning of your salvation, since he is truly the “first handful” of dough and you “the whole lump.” And if the first handful is holy, plainly its holiness will permeate the lump. - "Mystagogical Lectures 3.6"