In this scene Octavius is explaining who needs to die to Antony and Antony has a list of people who needed to die which included his brother.
Act 4 Scene 2
Most Noble brother you have done me wrong
Octavius is explaining to Antony that they are going to face strong soldiers. Antony uses a comparison to his horse and says as long as you train something or someone you can have strong soldiers.
Act 4 Scene 3
Away, slight man!
Must I tolerate all this
Pindarus is giving a message to Brutus that his master will visit him soon. Brutus responds to him by saying that he has no doubt that he will come to him.
Cassius approaches Brutus and tells him that he has wronged him. Brutus says that he would never wrong an enemy so why would he wrong a brother
Brutus and Cassius are arguing and Brutus tells him to go away and that he is little. Cassius responds surprised that he is saying this and asks the gods why he should tolerate it.