How we cite our quotes: (Act.Scene.Line)
Quote #4
Barabas: Entreat the Abbess to be entertained.
Abigail: How, as a nun?
Barabas: Ay, daughter, for religion
Hides many mischiefs from suspicion. (1.2.276-79)
Barabas is fighting fire with fire here: if Ferneze can steal from the Jews by using the talisman of religiosity, so can Abigail. While it makes perfect sense that you'd pretend to be a nun in order to sneak into a nunnery, Barabas remarks more broadly that people expect you're doing good if you act under the mantle of religion.
Quote #5
It's no sin to deceive a Christian,
For they themselves hold it a principle,
Faith is not to be held with heretics;
But all are heretics that are not Jews. (2.3.309-12)
It was a pretty common view among both Christians and Jews that promises made to people of other religions weren't actually binding—those considered heretics were 'faithless', and so you weren't obligated to "keep faith" by sticking to the promises you made them. That…sounds like a recipe for disaster.
Quote #6
\BARABAS: Are strangers with your tribute to be taxed?
KNIGHT 2: Have strangers leave with us to get their wealth?
Then let them with us contribute (1.2.59-61)
Well, no one's really right here. Barabas acts as though he owes Malta nothing, even though, as the Knight points out, his success has depended upon being allowed to live and work on Malta. The Knight, for his part, acts like the Jews are just being taxed like any normal citizen, when really they're being singled out.