In naʿqid qarīnatanā bi-ḥablin, the root ʿ-Q-D refers to literal tying. In ʿaqadū yamīnan, it denotes binding oneself through a sworn promise.
ExpressionMeaningʿAqd al-ḥablTying a ropeʿAqd al-yamīnSwearing a binding oath
The same root thus moves from a physical knot to a moral and social commitment within two adjacent verses.