What does the Bible say about asking God for a sign?

In Psalm 87, Jesus prays, 'Show me a token for good,' which illustrates that it's appropriate for believers to seek a spiritual sign from God. However, the sign should not be something visible or physical, as the Lord condemns those who seek signs as evidence for belief. Instead, believers are encouraged to ask God to reveal the truth of His Word and grant the Holy Spirit to open their spiritual eyes to understand the gospel. The true signs are those that affirm God’s love and grace toward us through Jesus Christ.