Albert Barnes Commentary 1 Samuel 25:22

"God do so unto the enemies of David, and more also, if I leave of all that pertain to him by the morning light so much as one man-child." — 1 Samuel 25:22 (ASV)

The concluding phrase signifies the utter destruction of a family and is correctly explained to mean “every male,” perhaps with the idea of including even the lowliest member of the household.