The psalmist says that because he muses on the God’s Torah all day long, he has “gained more insight than all his teachers” (119:99).
Here are some references to “insight” (sekel) in the Bible:
The first one comes at Gen 3:6: Eve perceived she would get “insight” from the tree.
Deut 32:29: “If only they were wise and would understand this
and discern what their end will be!”

1 Sam 25:3: “His name was Nabal and his wife’s name was Abigail. She wan an intelligent and beautiful women, but her husband was surly…”.
Is 52:13: “See, my servant will act wisely.”
Notice this too. The word can mean “prosper”: “Walk in obedience to him, and keep his decrees and commands, his laws and regulations, as written in the Law of Moses. Do this so that you may prosper in all you do and wherever you go” (1 Kgs 2:3).
Let us say “insight” describes at least this: a person who delights in hearing God’s Word learns it and flourishes in judgment, decisions, and direction.