Of > [By the]
4 The other two; Medina was her name,
Medina > "Mean", "Central" (Latin medius, middle); hence:
"Temperate"
5 A sober, sad, and comely courteous dame;
sad > grave, serious comely > decorous, decent
6 Who (rich arrayed, and yet in modest guise,
guise > appearance; demeanour; behaviour
7 In goodly garments, that her well became), 8 Fair marching forth in honourable wise,
wise > manner
9 Him at the threshold met, and well did enterprise.