Tis' my breeding!

Iago! Thou have made my life a mess. I told thee "let it not gall your patience, good Iago, that I extend my manners. 'Tis my breeding that gives me this bold show of courtesy." Why did thou not listen Iago? I did nothing wrong to you. I did not tell Othello to pick me over you for Lieutenant. You should have moved on and let it be. Instead thou allowed jealousy to take over. You planned in your mind as I greeted thee madam of my lord. I heard it some time later that 'tis was the thought running through they mind "he takes her by the palm. Ay, well said; whisper. With as little a web as this will I ensnare as great a fly as Cassio. Ay, smile upon her, do. I will gyve thee in thine own courtship. You say true, 'tis so indeed. If such tricks as these strip you out of your lieutenantry,it had been better you had not kissed your three fingers so oft, which now again you are most apt to play the sir in. Very good, well kissed, an excellent courtesy! 'Tis so indeed. Yet again your fingers to your lips? Would they were clyster-pipes for your sake."  Thy could not take my word that it was my breeding. Ay, you used it against me and the madam. You are the green-eyed monster Iago! 

Cassio to Iago
Act 2 i. 97-9
Iago
Act 2 i. 163-72
 Literary Devices Quote 1 (Cassio):
Pre-empting: Cassio is trying to avoid all arguments that can come from his bold greeting by assuring it was how he was brought up. Unfortunately for Cassio it did the opposite and gave Iago an idea as to how he will bring about chaos. As a reader this allows us to understand the type of person Cassio is and that he does not want Desdemona even though he whispered with her. Shows he is a character of order.
Literary Devices Quote 2 (Iago):
Simile: Iago is referring to the situation of Cassio's breeding as a web that will end up catching him like a fly. As the reader we know Iago is planning to use Cassio to bring about chaos.
Cause-and-effect Analysis: Iago is saying he will use the way Cassio was brought up and his kindness towards Desdemona against him and he believes Cassio may lose lieutenantry because of it. In fact I ago is counting on it. We as the reader are able to see how Iago will do things and it gives s a better understanding as to why things are happening when they do.