Ibn al-Qayyim (Raḥimahu Allāh) said, ❝The one who eats something takes on somewhat of its characteristics in his attitude and actions. Just as there is wisdom in what Allāh has created, there is also wisdom in what He has prescribed and commanded (His Sharīʿah). He has forbidden His slaves to eat unclean things because if they consume them, these things will become a part of them and they will be what they eat. When a person eats, he resembles what he eats, and what he eats becomes essentially a part of him.❞

In: At-Tibyān fī Aqsām al-Qur`ān 1/236

[Quote taken+edited from sheikh Sājid Aḥmed ʿOmar’s FB page]