He who shall hurt the little Wren Shall never be belov'd by Men.
This should seem pretty familiar. Injuring birds is bad—this is yet another point in the animal rights zone. It's a theme Blake has harped on before.
Overall, the takeaway is: if you're cruel to birds, you're probably not going to inspire real affection among other human beings either. Little acts of cruelty indicate bigger truths about someone's character or personality.
He who the Ox to wrath has mov'd Shall never be by Woman lov'd.
This is a weird one—though it's still related to the mistreatment of animals, like so many couplets before it.
The famous British writer G.K. Chesterton thought it was one of Blake's most ridiculous lines, and made fun of "the idea that the success of some gentleman in the society of ladies depends upon whether he has previously at some time or other slightly irritated an ox" (source).
But is it really that nuts? Is Blake actually talking about something specifically related to oxen? It seems that Blake might simply be saying that if you start trouble where there shouldn't be any—like in the peaceful world of oxen—people won't like you. It'll wreck your character—in this case, impacting some dude's ability to charm women.
Note that the previous couplet had to do with how men wouldn't like you if you went around hurting wrens—this one switches up the genders and the animals.