When approaching a new pair, proceed in four stages: (1) establish the senses; (2) compare letter identity, number, form and order; (3) identify the location and cause of any difference; and (4) explain the figure’s contribution to the message.
For «فتح / حتف», the senses are victory and death, the core letters are shared, their order changes, and the contrast praises a benefactor’s power toward allies and enemies. Thus it is a clear instance of qalb.
For «أقم / القيم», investigation of the root reveals an ishtiqāq relationship. Classifying from sound alone could lead to a less accurate designation.