John Wesley on Genesis 49:9

Judah is a lion's whelp - The lion is the king of beasts, the terror of the forest when he roars; when he seizeth his prey, none can resist him; when he goes up from the prey, none dares pursue him to revenge it. By this it is foretold that the tribe of Judah should become very formidable, and should not only obtain great victories but should peaceably enjoy what was got by those victories. Judah is compared not to a lion rampant, always raging but to a lion couching, enjoying the satisfaction of his success, without creating vexation to others.