Why did he say "after me
Malbim: After whom did you, Melech Yisrael, go out to chase? And also now, whom do you pursue?
Why did David compare himself to a dead dog?
Radak: Compared to you, I am considered like a dog - and not alive, rather, dead.
Radak citing Targum Yonasan: [You pursue] a weak person.
Malbim: You went out after a dog, a loyal servant to its master. 1
Why did he say "dead"? When it is dead, it cannot serve its master! (PF)
Why did David compare himself to a flea?
Targum Yonasan: [You pursue] a commoner. Radak - David compared himself to something trifling and weak. One who finds a flea on his garment or on his body, he pursues it, for it jumps from place to place. What attribute and what Gevurah is it for you to pursue me, like one who chases a flea?!
Malbim: Now you pursue someone weak without importance, like a flea that jumps from place to place when one wants to seize it - and not against many fleas (David's 600 men), rather, one flea!
