According to Manu 2.6,
vedo'khilo dharmamūlaṃ smṛtiśīle ca tadvidām |
ācāraścaiva sādhūnāmātmanastuṣṭireva ca || 6 ||
The entire Veda is the root-source of Dharma; also the Conscientious Recollection of righteous persons versed in the Veda, the Practice of Good (and learned) Men, and their self-satisfaction.—(6)
It's proclaiming the entire Veda to be the root-source of dharma. How the Vedas, that too collectively, bring about convictions about dharma and adharma? There are many portions in the Vedas which ain't apparently dealing with dharma. Moreover, smṛti-s ain't included in the Vedas but mentioned separately in the given verse.
I wonder how do the entire Vedas (including samhitā, etc.) deal with dharma? Like, do we have even handful of instances where the Samhitā-s are apparently dealing with dharma? So, what are the implications and connotations of "the entire Vedas" here?