2 Samuel 12:16

David therefore besought God for the child
Perhaps went into the tabernacle he had built for the ark, and prayed to the Lord to restore the child, and spare its life; for though the Lord had said it should die, he might hope that that was a conditional threatening, and that the Lord might be gracious and reverse it, ( 2 Samuel 12:22 ) ;

and David fasted:
all that day:

and went in;
to his own house from the house of God:

and lay all night upon the earth;
would neither go into, nor lie upon a bed, but lay on the floor all night, weeping and praying for the child's life, and especially for its eternal welfare: he having through sin been the means of its coming into a sinful and afflicted state.