30 And Saul's anger was kindled against Jonathan, and he said to him, Son of the perverse rebellious woman, do not I know that thou hast chosen the son of Jesse to thine own shame and to the shame of thy mother's nakedness? 31 For as long as the son of Jesse lives upon earth, thou shalt not be established, nor thy kingdom. And now send and fetch him to me, for he must die. 32 And Jonathan answered Saul his father, and said to him, Why should he be put to death? what has he done? 33 Then Saul cast the spear at him to smite him; and Jonathan knew that it was determined by his father to put David to death.
Matthew Henry's Commentary on 1 Samuel 20:30-33
Commentary on 1 Samuel 20:24-34
(Read 1 Samuel 20:24-34)
None were more constant than David in attending holy duties; nor had he been absent, but self-preservation obliged him to withdraw. In great peril present opportunities for Divine ordinances may be waved. But it is bad for us, except in case of necessity, to omit any opportunity of statedly attending on them. Jonathan did wisely and well for himself and family, to secure an interest in David, yet for this he is blamed. It is good to take God's people for our people. It will prove to our advantage at last, however it may now be thought against our interest. Saul was outrageous. What savage beasts, and worse, does anger make men!