The truth will out
I'm Lancelot. I'm a servant and clown, but my real job is fooling around, making smart-aleck comments, and bagging on other characters. And you know what I think?
Nay, indeed, if you had your eyes, you might fail of
the knowing me: it is a wise father that knows his
own child. Well, old man, I will tell you news of
your son: give me your blessing: truth will come
to light; murder cannot be hid long; a man's son
may, but at the length truth will out. (2.2.69-74)
Who Said It and Where
Lancelot Gobbo, Shylock's servant, hates his job. But can you blame him? Shylock is condescending, particular, and just plain rude. Lancelot stands before Shylock's house, having a very serious and hilariously muddled conversation with himself about his desire to quit his job.
He says his conscience tells him to stay with Shylock out of loyalty, but some fiend in his brain is telling him he should run away. His reasoning's a bit crooked here. Since his conscience tells him to stay with the devil incarnate, clearly the thing to do is run away, loyalty be damned.
Just then Old Gobbo—Lancelot's dad, who is mostly blind—shows up looking for his son. He can't tell that he's talking to his son because he's blind and all. Lancelot decides to have some fun with his father before he reveals his identity (what a meanie). He teases that the old man should speak of "Master" Lancelot, not just Lancelot. Old Gobbo is quick to point out that young Gobbo is no Master Lancelot, but just plain old Lancelot, the son of a poor man. Aw, shucks, he didn't go for it.
So Lancelot tries something else. He tells Old Gobbo the oh so hilarious joke that his son is dead. Lancelot finally reveals who he is, and there's much ado about how much he's grown. Old Gobbo has brought Shylock a present, and Lancelot suggests his dad give the present to Bassanio instead, as Bassanio is Lancelot's new chosen master. Being Shylock's servant has left him in such a state that you can count each of his ribs (i.e., he's not paid enough to eat properly).