The answer is: Those without fins and scales

Deut 14:9

In Deuteronomy 14:9, God's dietary laws outline which aquatic creatures are acceptable for consumption, clearly defining those without fins and scales as unclean. This classification helps illustrate the meticulous attention given to purity laws in ancient Israelite culture. It’s fascinating to consider the adaptation of these laws over centuries and how they reflected a holistic understanding of health, sustainability, and community identity.

Historically, having markers like fins and scales can signify stronger, healthier fish varieties often found in clean waters, which would be crucial for the sustenance of nomadic tribes. Interestingly, the requirement of both fins and scales often excludes creatures we would easily find in modern fish markets, such as catfish and shellfish, or even sushi favorites that certainly have their own appeal in contemporary pounds.

This custom isn't just an arbitrary set of rules either; it reveals deep connections to ritual purity and shape societal norms surrounding meal morality, community cohesion, and sacred discernment—concepts still echoed across various cultures today. Also worth pondering is how this ancient text resonates with modern-day discussions about environmental conservation and protecting aquatic life.

Reflect on the larger metaphor of clean and unclean—perhaps serving as a reminder to evaluate more than just dietary habits but choices about our lives and environments. Spiritual cleanliness can serve a significant role in how we engage with the world and combat life's challenges. Each ancient guideline aimed to cultivate a conscientious community, still very much a valuable lesson today.