Come to the king - The king as a judge was accessible to all his subjects (2 Samuel 15:2; compare 1 Kings 3:16).
Matthew Henry
Concise Bible Commentary
We may notice here, how this widow pleads God's mercy, and his clemency toward poor guilty sinners. The state of sinners is a state of banishment from God. God pardons none to the dishonour of his law and justice, nor any who are impenitent; nor to the encouragement of crimes, or the hurt of others.
SDA Bible Commentary (limited)
Volume 1-7
3. Come to the king. The king was the supreme judge of the land, and accessible to all his subjects. He was expected to assist them in their difficulties.