1 Samuel 31:13

And they took their bones, and buried them under a tree at Jabesh, and fasted seven days.

And they took their bones, and buried them under a tree at Jabesh,.... For though they burned the bodies, yet so as to preserve the bones; and these, together with the ashes of the parts burnt, they gathered up, and buried under a tree near this city; this tree is said to be an oak, 1 Chronicles 10:12; so Deborah, the nurse of Rebekah, was buried under an oak, Genesis 35:8. The Jews generally interred their dead under some oak, as aforementioned writer observes {q}; pleased perchance with the parallel, as he expresses it, that as these plants, seemingly dead in winter, have every spring an annual resurrection, so men's dry bones shall have new sap put into them at the day of judgment:

and fasted seven days; not that they ate and drank nothing all that time, but they fasted every day till evening, as the Jews used to do; so long it seems a man may live without eating, but not longer;

See Gill on "Exodus 24:18" and

see Gill "1 Kings 19:8"; this they did, as Kimchi thinks, in memory of the seven days Nahash the Ammonite gave them for their relief, in which time Saul came and saved them, 1 Samuel 11:3.

{q} Pisgah-Sight of Palestine b. 2. ch. 2. p. 82.