What does Sampson do (not say) that aggravates Abram and Balthasar?

Sampson aggravates Abram and Balthasar by saying 'draw it if you be my men, thy washing blow'.

Explanation:

This is the opening scene and then starts the fight between the servants, Abram and Balthasar. When the servants arrive, Sampson says if they want to fight, his employers are as good as them. But Abram says they are no better. Then Sampson bites his thumb, which is considered as a rude action. Insulted Abram confronts Sampson and the fight begins. Benvolio enters and tried to stop but Tybalt causes more trouble. Tybalt calls Benvolio a coward and this provokes Benvolio and he raises his sword and fights with Tybalt.