1 Samuel 20:30

Who would not have loved him [David], when they saw how dear he was to his friends? For as he truly loved his friends, so he thought that he was loved as much in return by his own friends. No, parents put him even before their own children, and children loved him more than their parents. Therefore Saul was very angry and strove to strike Jonathan his son with a spear because he thought that David's friendship held a higher place in his esteem than either filial piety or a father's authority.

For love "doth nothing unseemly," but as it were with certain golden wings covereth up all the offences of the beloved. Jonathan loved David; and hearing his father say, "Thou son of damsels that have run away from their homes, thou womanly bred," he was not ashamed, though the words be full of great reproach. For what he means is this: "Thou son of mean harlots who are mad after men, who run after the passers-by, thou unnerved and effeminate wretch, who hast nothing of a man, but livest to the shame of thyself and the mother who bare thee." What then? Did he grieve at these things, and hide his face, and turn away from his beloved? Nay, quite the contrary; he displayed his fondness as an ornament. And yet the one was at that time a king, and a king's son, even Jonathan; the other a fugitive and a wanderer, I mean, David. But not even thus was he ashamed of his friendship. "For love doth not behave itself unseemly." Yea, this is its wonderful quality that not only it suffers not the injured to grieve and feel galled, but even disposes him to rejoice. Accordingly, he too, of whom we are speaking, after all these things, just as though he had a crown put on him, went away and fell on David's neck. For love knows not what sort of thing shame may be. Therefore it glories in those things for which another hides his face. Since the shame is, not to know how to love; not, when thou lovest, to incur danger and endure all for the beloved.

For that commendable friendship which maintains virtue is to be preferred most certainly to wealth or honors or power. It is not apt to be preferred to virtue indeed, but to follow after it. So it was with Jonathan, who for his affection's sake avoided neither his father's displeasure nor the danger to his own safety.

But Saul, angry against Jonathan, etc. The elders of the Synagogue, angry against the assembly of spiritual people, call his mother the Church by the name of an adulteress, because she has nobly taken Christ instead of Moses, the bridegroom instead of the friend of …

It will prove to our advantage at last, however for the present it may be thought a disparagement, and a prejudice to our secular interest. It is probable Saul knew that David was anointed to the kingdom by the same hand that anointed him, and then not Jonathan, but himself, was the fool, to think to defeat the counsels of God.