Where created_at > $this->created_at in relationship

Hi. I have 3 tables:

1. products - just a simple table with product ids.
2. product_checks. regulary, all product are checked if their data is fresh and updated info is stored in this very table. one line per each check. some sort of history of data changes.
3. prduct_trackers. some users can "subscribe" for some products from specific period of time.

in the product_tracker model i have a relationship:

class ProductTracker extends Model { public function product_checks(): HasMany { return $this->hasMany(ProductCheck::class, 'product_id', 'product_id') ->where('created_at', '>', $this->created_at)); } }

The idea is that: if I call the product_checks relationship, I need to get all checks which were created AFTER a respective tracker was created. I thougth, I can use $this->created_at but $this return null and as result this approach doesn't work.

Just one more remark. I'm talking about a case when product_checks are to be joined being eager loaded using 'with'.