«رَشِيقَةَ الْقَدِّ، أَسِيلَةَ الْحَدِّ»
Graceful in form, smooth and fine at the edge.
The adjectives could describe a delicate human figure, yet ḥadd also denotes a sharp edge. The speaker deliberately applies human-style praise to an implement, making its identity part of a verbal riddle.