Some people are unworthy of reaching Heaven by the highway;.
The gates of Heaven will not open on their behalf.
Yet they are not rejected absolutely.
God is willing to dig for them a special path by which they can reach Him.
They must go through a secret tunnel, entering the Palace from beneath the Throne of Glory.
Their only way to reach Heaven is to dig and tunnel through until they succeed in breaking a way through to God.
God allows everyone to reach Him – our task is to take advantage of the small opening He offers.
–Rabbi Adin Steinsaltz