(Alternately: Yonatan) Jonathan; the son of Shaul, who befriended David, and eventually chose loyalty to David over his own succession to the throne. His relationship with David is described in the famous “Haftarah” (Supplementary Shabbat Reading from the Prophets), which is read on Shabbat Erev Rosh Chodesh, which discusses the agreement between Yehonatan and David as to how Yehonatan would indicate to David his father’s feelings concerning him. The “Haftarah” concludes with the following oath which Yehonatan took with David, “What the two of us have sworn in the Name of Hashem – saying, ‘Hashem shall be between me and you, and between my children and your children’ – shall be forever.” (“Shmuel Aleph”/Samuel I 20:42)
The relationship is also described by David himself in his eulogy for Yehonatan, “My heart is greatly pained because of you, my brother, Yehonatan, you were so very pleasant to me; my love for you exceeds that of my love for women.” (“Shmuel Beit”/Samuel II 1:26).
And it is also described in Pirkei Avot as the example of love which is dependent on no specific cause, but which arises from pure affection of one for the other, which endures forever.” (Avot Ch. 5: Mishnah 19)