1 Kings 15:23
The rest of all the acts of Asa, and all his might, and all that he did, and the cities which he built, are they not written in the book of the chronicles of the kings of Judah? Nevertheless in the time of his old age he was diseased in his feet.
After the first eleven chapters on Solomon, 1 Kings together with all of 2 Kings gives the history of the kings after the division of the kingdom under Rehoboam, whose imprudent stubbornness lost a large portion and left the two kingdoms of Israel and Judah continuing together sometimes at war and sometimes at peace until Israel was obliterated in 721 B.C. and Judah was besieged and conquered at Jerusalem by Nebuchadnezzar in 606 B.C. with final captivity in 588 B.C. The same period is repeated in Chronicles, except that after the division no further mention is made of the wicked kingdom of Israel. Within that history, the verse belongs to the history of the two separate kingdoms of Judah and Israel for about eighty years, from the revolt of the ten tribes to the death of Jehoshaphat. It forms part of the accounts of the reigns of several kings both of Judah and of Israel in that span.
More specifically, the verse belongs to the account of Asa's reign in Judah, which follows the reign of Abijah and stands alongside the reigns of Nadab, Baasha, Elah, Zimri, Omri and the wicked Ahab in Israel after the division. Asa's reign, to which the verse belongs, was largely for the better. The verse records that Asa's deeds, strength, and building projects including the cities he built were documented in the book of the chronicles of the kings of Judah.
The verse records that nevertheless in the time of his old age Asa suffered from a disease in his feet. The accounts of Abijah and Asa are given more fully in Chronicles. The foot disease pictures Christians who neglect the gospel remedy and develop spiritual troubles, like feet made sore or diseased, and following the gospel prescription can remedy them.