Walk through Amos, verse by verse, with the great Bible Commentaries of Matthew Henry (1662 - 1714) & Adam Clarke (1760 - 1832)
3:4
Will a lion roar in the forest, when he hath no prey? will a young lion cry out of his den, if he have taken nothing? KJV
{Whether a lion shall roar in a forest, no but he have prey? Whether the whelp of a lion shall give voice from his den, no but he take anything?} Wycliffe's Bible
Will a lion roar - Should I threaten such a judgment without cause?
“Will a lion roar in the forest when he has no prey in view? No: he roars upon his prey. Nor will a young lion cry out of his den if the old lion have taken nothing to bring home to him; nor would God thus give you warning both by the threatenings of his word, and by less judgments, if you had not by your sins made yourselves a prey to his wrath, nor if he were not really about to fall upon you with desolating destroying judgments.”
Will a lion roar - Should I threaten such a judgment without cause?
“Will a lion roar in the forest when he has no prey in view? No: he roars upon his prey. Nor will a young lion cry out of his den if the old lion have taken nothing to bring home to him; nor would God thus give you warning both by the threatenings of his word, and by less judgments, if you had not by your sins made yourselves a prey to his wrath, nor if he were not really about to fall upon you with desolating destroying judgments.”
