Albert Barnes Commentary 2 Kings 4:16

"And he said, At this season, when the time cometh round, thou shalt embrace a son. And she said, Nay, my lord, thou man of God, do not lie unto thy handmaid." — 2 Kings 4:16 (ASV)

Do not lie - Compare a similar incredulity in Genesis 17:17; Genesis 18:12; and Luke 1:20. The expression “do not lie,” which seems harsh to us, is consistent with the plain, straightforward simplicity of ancient speech. It would have meant no more than to “deceive” (compare the cross-reference).