At that time - The phrase here connects the narrative which follows with Jeroboam's persistence in his evil courses. The event related is the first judgment upon him for his obduracy, the beginning of the cutting off of his house from the face of the earth.
Abijah - We see by this name that Jeroboam did not intend to desert the worship of Yahweh, since its signification is "Yahweh is my father," or "Yahweh is my desire" Job 34:36.

Abijah - fell sick - This was but a prelude to the miseries which fell on the house of Jeroboam; but it was another merciful warning, intended to turn him from his idolatry and wickedness.

At that time Abijah, the son of Jeroboam, fell sick. Being smitten of God with some disease, as a punishment of Jeroboam's sin; how long this was after the above things were done cannot be said.

"At that time," when Jeroboam did evil, his child sickened. When sickness comes into our families, we should inquire whether there may not be some particular sin harboured in our houses, which the affliction is sent to convince us of, and reclaim us from. It had been more pious if he had desired to know wherefore God contended with him; had begged the prophet's prayers, and cast away his idols from him; but most people would rather be told their fortune, than their faults or their duty. He sent to Ahijah, because he had told him he should be king. Those who by sin disqualify themselves for comfort, yet expect that their ministers, because they are good men, should speak peace and comfort to them, greatly wrong themselves and their ministers. He sent his wife in disguise, that the prophet might only answer her question concerning her son. Thus some people would limit their ministers to smooth things, and care not for having the whole counsel of God declared to them, lest it should prophesy no good concerning them, but evil. But she shall know, at the first word, what she has to trust to. Tidings of a portion with hypocrites will be heavy tidings. God will judge men according to what they are, not by what they seem to be.

AHIJAH DENOUNCES GOD'S JUDGMENTS AGAINST JEROBOAM. (1Ki. 14:1-20)
At that time--a phrase used often loosely and indefinitely in sacred history. This domestic incident in the family of Jeroboam probably occurred towards the end of his reign; his son Abijah was of age and considered by the people the heir to the throne.

Reign of Jeroboam. - Vv. 1-18. Ahijah's prophecy against Jeroboam and the kingdom of Israel. - As Jeroboam did not desist from his idolatry notwithstanding the threatened punishment, the Lord visited him with the illness of his son, and directed the prophet Ahijah, to whom his wife had gone to ask counsel concerning the result of the illness, to predict to him not only the cutting off of his house and the death of his sick son, but also the thrusting away of Israel out of the land of its fathers beyond the Euphrates, and in confirmation of this threat caused the sick son to die when the returning mother crossed the threshold of her house again.

At that time - Presently after the things described in the former chapter; which, though related in the beginning of his reign, yet might be done a good while after it, and so Ahijah the prophet might be very old, as he is described to be 1-Kings 14:4. It is probable he was his eldest son.