2 Samuel 3:35 (BSB)

Then all the people came and urged David to eat something while it was still day, but David took an oath, saying, “May God punish me, and ever so severely, if I taste bread or anything else before the sun sets!”

From 2 Samuel 3. Also in the ESV.

Commentary on 2 Samuel 3:35

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on 2 Samuel 3:22-39: We have here an account of the murder of Abner by Joab, and David's deep resentment of it. I. Joab very insolently fell foul upon David for treating with Abner. He happened to be abroad upon service when Abner was with David, pursuing a troop, either of Philistines or of Saul's party; but, upon his return, he was informed that Abner was just gone (Sa2...
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on 2 Samuel 3:35: And when all the people came to cause David to eat meat while it was yet day,.... The custom was to bury in the daytime, and after the funeral was over to provide and send in food to the relations of the deceased, and come and eat with them; as was also the usage with the Greeks and Romans (w); See Gill on Jer 16:5...
• Geneva Bible Notes (Reformed), Geneva Bible Study Notes on 2 Samuel 3:35: And when all the people came to cause David to eat meat while it was yet day, David sware, saying, So do God to me, and more also, if I taste bread, or ought else, till the sun be down. (o) According to their custom, which was to feast at burials.
• Keil & Delitzsch (Lutheran), Biblical Commentary on the Old Testament on 2 Samuel 3:6-39: 2Sa 3:6-39 Decline of the House of Saul. - 2Sa 3:6-11. Abner’s quarrel with Ishbosheth. - During the war between the house of Saul and the house of David, Abner adhered firmly to the house of Saul, but he appropriated one of Saul’s concubines to himself.