After the opening Takbir (Takbirat al-Ihram), does a person abandon worldly matters or ponder the Kingdom of God?

Humility (khushu') in prayer means that the heart is present in it, and that the worshiper is mindful of this great act of worship. It is the essence and spirit of prayer, and a cause for increasing reward. Allah has praised those who are humble in their prayers. Among the things that help achieve humility is to empty one's heart for Allah when approaching prayer, and to be mindful of standing before Allah, who knows what is apparent and what is hidden. The worshiper is rewarded for his prayer according to his humility in it; he may only be rewarded for a tenth of his prayer, or less, or more.