Then-Samuel took a vial of oil. — The vial was a narrow-necked vessel, from which the oil flowed in drops. It was, of course, no common oil which the prophet used on this momentous occasion, but the oil of holy ointment, the sacred anointing oil which was used at the consecration of the priests, and also of the Tabernacle and the sacred vessels. (See Exodus 29:7; Exodus 30:23-33, &c.) The solemn anointing took place in the ceremony of consecration in the case of some, but not of all, the Hebrew sovereigns. We hear of it at the accession of David, Absalom, Solomon, Joash, Jehoahaz, And Jehu. In cases of regular succession the anointing was supposed to continue its effect — that is, the regular succession needed no new anointing. Hence it is that only the above named kings are mentioned as having been anointed, all founders of dynasties or irregularly advanced to the throne. (See Erdman in Lange here.)
And kissed him. — Rather as a customary sign of reverential homage than as a mark of affection, which at that early date of their acquaintance it was hardly possible to assume that the old man felt for the younger. (Compare Psalms 2:12 : “Kiss the son, lest he be angry”: that is, “Do homage, O ye kings of the earth, to Him who is your anointed King.”)
The Lord hath anointed thee. — Samuel replies to the look and gesture of extreme astonishment with which the young Saul received the anointing and the kiss with these words: “Do you mutely ask me why I pay you this formal homage? why I salute you with such deep respect? Is it not because you are the chosen of the Eternal? Are you still incredulous respecting your high destiny? See now, as you go on your way home, you will meet with three signs; they will prove to you that what I do, I do not of myself, but in obedience to a higher power.”