Focus on Habakkuk and the Angel (Bernini) and discuss the Description.
In spite of the narrow niche Bernini produced a lively and dramatic composition. Habakkuk is seated on a rock with his lunch basket at his side and pointing towards the direction he wants to go, while the young and beautiful angel is leaning out of the niche, lifting Habakkuk's head by his hair and pointing toward Daniel on the other side of the chapel. The prophet is portrayed as a bearded, older but still strong man.
Bernini depicted a story from the Book of Daniel which tells how God saved Daniel from starving through the miraculous appearance of Prophet Habakkuk in the lions' den (Daniel 14:33-36):"Now the prophet Habakkuk was in Judea; he had made a stew and had broken bread into a bowl, and was going into the field to take it to the reapers. But the angel of the Lord said to Habakkuk, “Take the food that you have to Babylon, to Daniel, in the lions’ den.” Habakkuk said, “Sir, I have never seen Babylon, and I know nothing about the den.” Then the angel of the Lord took him by the crown of his head and carried him by his hair; with the speed of the wind he set him down in Babylon, right over the den."
After the grateful Daniel ate his dinner, the angel of the Lord carried Habakkuk back to his place. This story is part of the Greek Additions to Daniel comprising chapter 14 in the Vulgate. Iconographically the statue of Habakkuk has its counterpart in the chapel in the Raphaelesque statue of Elijah which also shows a prophet saved from hunger by the angel of the Lord.
Another reason why Bernini probably chose to picture this episode is that the Chigi Library contained the only known Septuagint text of the Book of Daniel from which the story was drawn, the Codex Chisianus 45. Curiously two early guides of the basilica, those of Alberici (1600) and Landucci (1646), identified the then-existing statues of the chapel as Jonah and Habakkuk, instead of their real subjects, Jonah and Elijah. The mistake could be an indication that a statue of Habakkuk had been part of the iconographic program of the chapel at an earlier stage.
Book of Daniel Septuagint Vulgate Raphael statue of Elijah Chigi Library Additions to Daniel Habakkuk Elijah Codex Chisianus 45