"Six years shall he serve" — from this simple statement, the Mekhilta derives a ruling about sick bondsmen. If a Hebrew bondsman fell ill and was unable to work for the entire six-year period, he must make up the time he lost. He does not simply walk free after six calendar years if he spent those years incapacitated.
The logic is straightforward: the Torah says he shall "serve" for six years. Service means actual labor. Time spent bedridden is not service. Therefore, the clock pauses during illness and resumes when the bondsman recovers.
The Mekhilta then extends the same principle to a bondsman who ran away and was later recaptured. Just as illness interrupts the count, so does flight. The bondsman cannot reduce his obligation by escaping for a few years and then claiming his six years are up when he is caught.
Both rulings flow from the same interpretive move: reading "six years shall he serve" with emphasis on the word "serve." Scripture speaks of one who is able to serve. Only active service counts toward the six-year total. This prevented abuse of the system from both directions. A genuinely sick bondsman was not freed prematurely — but neither was his illness held against him as punishment. The clock simply stopped and restarted. Time served was time worked. Everything else was a pause, not a penalty.