This is one of those times when consideration of the structure of the passage might reveal important truths. 

A. v. 15, Brothers "see father" dead and say to Joseph (double action)

  B. v. 16, they send a message* 

    C. v. 17a, Please forgive servants of God.     

      D. v. 17b, Joseph wept*

    C'. v. 18, Brothers: we are your servants.

  B'. v. 19-21a, Joseph's response to "father's" message

A'. v. 21b, He comported them and spoke kindly (double action).  

 

* Joseph weeps 7 time throughout the story (Gen. 37 - 50): 

1. 42:24 - 1st time seeing brothers

2. 43:30 - 2nd visit - banquet with brothers

3. 45:2 - "I am Joseph" 

4. 45:14 - Joseph weeps over Benjamin 

5. 45:15 - Joseph weeps over his brothers

6. 50:1 - Death of Jacob

7. 50:17 - Brothers try to trick him to forgive them. 

Rev. Thomas Whitelaw, D.D. puts it this way: "[Joseph weeps] pained that they for single moment have entertained such suspicions against his love". (The Pulpit Commentary, Genesis, Funk & Wagnalls Company, London and New York, 1944, p. 539).