Albert Barnes Commentary Amos 5:19

"As if a man did flee from a lion, and a bear met him; or went into the house and leaned his hand on the wall, and a serpent bit him." — Amos 5:19 (ASV)

As if a man, did flee from a lion - The Day of the Lord is a day of terror on every side. Before and behind, without and within, outdoors under the roof of heaven, or under the shelter of his own house, everywhere is terror and death.

The Syrian bear is said to have been more fierce and savage than the lion. For its fierceness and voracity (Daniel 7:5), God made it, in Daniel’s vision, a symbol of the empire of the Medes.

From both lion and bear there might be escape by flight. When the man had leaned his hand trustfully on the wall of his own house, and a serpent bit him, there was no escape. He had fled from death to death, from peril to destruction.