Gen 18 - More Scriptural proof the laws (Torah) existed long before Mt. Sinai. Especially Gen 26:5.

The laws (Torah) existed long before Mt. Sinai.

How could Abraham know to do what Gen 26:5 says:

Gen 26:5
Because Abraham obeyed Me and kept My charge, My commandments, My Statutes and My Laws."

Also:

Deut 6:25
"And it will be righteousness for us if we are careful to observe all this commandment before the LORD our God, just as He commanded us.