The Lord himself will give you this sign

In today's first reading (Isaiah 7:10-14), King Ahaz refuses to ask the Lord for anything, because he does not trust the Lord.

Bad for him, but good for us, because this was God's response:

Therefore the Lord himself will give you this sign:
the virgin shall conceive and bear a son,
and shall name him Emmanuel.

This reminds us that God knows what we need better than we do ourselves, and that if we are faithful in our prayer, open to his will and trusting in his love, God can do things for us that are beyond our imagination.

For nothing will be impossible for God.