Into the midst of the house, or, into the house; for the midst is not always taken exactly, and mathematically, but for any part within, as Genesis 48:16 Exodus 8:22 Joshua 3:17. As though they would have fetched wheat; which was laid up in public granaries in the king's house, and was fetched thence by the captains and commanders of the army for the pay of their soldiers, who in those ancient times were not paid in money, but in corn, as is well known. Upon this pretence they were admitted into the house, and so went from room to room, to the place where the king lay. Rechab and Baanah escaped; which was not difficult to do, when the king was left alone; either because he desired to compose himself to rest or sleep; or because his guards, if he had any, were very small and negligent, now, at least, in his declining and forlorn condition.
Related Commentaries of 2 Samuel 4:6
2 Samuel 4:6
6 And they came thither into the midst of the house, as though they would have fetched wheat; and they smote him under the fifth rib: and Rechab and Baanah his brother escaped.