swear - literally, “lift up,” namely, his hand; the gesture used in solemn attestation. Or, his voice, that is, answer; so Vulgate.
healer - of the body politic, incurably diseased (Isa 1:6).
neither ... clothing - so as to relieve the people and maintain a ruler’s dignity. A nation’s state must be bad indeed, when none among men, naturally ambitious, is willing to accept office.