子であり、しもべ

Tanach applies an unusual number of relational titles to the Davidic figure, and they pull in different directions. Son implies nearness and inheritance. Servant implies subordination and task. King implies command. Prophet implies receptivity. Teacher implies patience. Man implies limit.

In most people these compete. Intimacy erodes deference; command erodes listening; certainty erodes teaching. The sources present Moshiach as the person in whom they do not compete, and this — rather than any single superlative — is the actual claim about his stature.

Son and servant are the same posture, seen twice

The apparent tension between son and servant dissolves once you notice what they have in common: neither one owns himself. A son inherits; he does not originate. A servant executes; he does not author. Both words describe a life whose meaning is received.

What distinguishes them is temperature, not structure. Servant is the word for the relationship viewed from the side of duty. Son is the same relationship viewed from the side of love. Torah uses both about David and about Israel, often within a few verses, because the relationship genuinely has both faces.

Why the combination is safe

A king who is only a king becomes a tyrant, because there is nothing above his judgement. A servant who is only a servant becomes an administrator, because there is nothing personal in his obedience. A son who is only a son becomes an heir who assumes the estate is his to spend.

Hold all three and each corrects the others. Sonship keeps the servant from becoming mechanical. Servanthood keeps the son from becoming entitled. Kingship gives both of them a world to act in. And underneath all three sits the same fact: he belongs to Hashem before he belongs to the office.

This is also why the prophetic register — Ruach Hashem — does not turn him into an escapist. Prophecy in Tanach is almost never a flight from the world; it is a summons back into it with worse news and better instructions. The one who receives most is sent furthest down.