John Gill Commentary 1 Kings 14:5

"And Jehovah said unto Ahijah, Behold, the wife of Jeroboam cometh to inquire of thee concerning her son; for he is sick: thus and thus shalt thou say unto her; for it will be, when she cometh in, that she will feign herself to be another woman." — 1 Kings 14:5 (ASV)

And the Lord said to Abijah
Either in a dream, or by an impulse upon his mind, before Jeroboam's wife came in:

behold, the wife of Jeroboam comes to ask a thing of you for her
son, for he is sick ;
to know whether he will recover or not:

thus and thus shall you say to her ;
as after expressed in some following verses:

for it shall be, when she comes in, that she shall feign herself to be
another woman ;
to the people that let her in, and introduce her to the prophet, and to the prophet himself; pretend herself to be a countrywoman come to ask a question of the prophet concerning her son that was ill of a disease.