إِنَّ تَيْسِيرَ السَّبِيلِ خِدْمَةٌ لِلنَّاسِ، وَخِدْمَةُ النَّاسِ أَمَانَةٌ.
Facilitating passage serves people, and service to people is a trust.
The first clause categorizes a specific act as public service; the second frames such service in a broader ethical principle. When used to reinforce the preceding directives, the general maxim can carry a tadhyīl-like concluding effect.
Still, generality alone does not prove technical tadhyīl: the added proposition should embrace and support the earlier meaning. Nor does the presence of “inna” automatically convert every emphatic statement into a rhetorical epilogue.