What does 1 Kings 3:8 mean?

In Gibeon, Yahweh appeared to Solomon in a dream by night; and God said, “Ask for what I should give you.”

Solomon said, “You have shown to your servant David my father great loving kindness, because he walked before you in truth, in righteousness, and in uprightness of heart with you. You have kept for him this great loving kindness, that you have given him a son to sit on his throne, as it is today.

Now, Yahweh my God, you have made your servant king instead of David my father. I am just a little child. I don’t know how to go out or come in.

Give your servant therefore an understanding heart to judge your people, that I may discern between good and evil; for who is able to judge this great people of yours?”

This request pleased the Lord, that Solomon had asked this thing.

God said to him, “Because you have asked this thing, and have not asked for yourself long life, nor have you asked for riches for yourself, nor have you asked for the life of your enemies, but have asked for yourself understanding to discern justice;