رَجَعَ تَاجِرٌ إِلَى دُكَّانِهِ مُسْرِعًا. ظَهَرَ خَلَلٌ فِي مِيزَانِهِ.
A merchant hurried back to his shop. A fault had appeared in his scale.
The first statement can suggest the implied question “Why did he hurry back?”. If the following report is intended to answer that question, it can serve as explanatory resumption (istiʾnāf bayānī), naturally expressed without a coordinating wāw.
The implied connection is contextual rather than automatic. If the second clause is not given as an answer, or the first does not naturally raise that question, one should not impose the label merely because two clauses are adjacent.