The Prophet ﷺ first pointed to an ordinary event, called Abu Dharr by name, received his response, and taught through that event. يَا أَبَا ذَرٍّ is a form of address; لَبَّيْكَ signals attentive readiness to respond. The brief dialogue made the illustration memorable.
Carefully chosen observations help make abstract meanings understandable. But a comparison supports only the point expressed in the report; it does not establish that a particular number of leaves corresponds to a fixed number of sins, or that the weather has a special ritual role.