Halt here means limping and is a different and much older word to the one meaning to stop (which was originally a German military term of the late sixteenth century). It has long been archaic. We know it today almost exclusively in the set phrases the halt and the lame and the halt, the lame and the blind, though we do retain halting in phrases such as halting speech, where it means slow and hesitant.
If asked, I’d guess most people would plump for a biblical origin for the expressions. They certainly sound biblical. But it turns out not to be so. The individual words halt and lame certainly figure in the King James version of 1611 and in earlier versions, but nowhere together. This is one appearance of halt in that work:
It is better for thee to enter into life halt or maimed, rather than having two hands or two feet to be cast into everlasting fire.
However, their absence doesn’t imply that the expressions weren’t then in existence. In fact, they seem to be older: I’ve found an example of the halt and the lame in the poem Cursor Mundi from Northumbria in the fourteenth century.
The word is a Germanic one that Old English spelled as halt or healt; it’s from the verb healtian, which meant to walk with a limp. A writer in 1868 who noted that “He halted slightly in his walk” didn’t meant that he kept stopping, but that he limped a little. That, you may think, makes the halt and the lame a tautology.
Many dictionaries do seem to equate the terms, defining halt as meaning lame. But the Oxford English Dictionary defines one meaning of lame as “disabled in the foot or leg, so as to walk haltingly or be unable to walk”, a higher level of disability than just a limp. Dr Johnson, in his Dictionary of 1755, says likewise that halt means “to be lame”; however, he defines lame as “crippled; disabled in the limbs”, again a more severe affliction than the way that halt seems to have been used. It would seem that halt referred to the effect and lame to the cause: he walked haltingly because he was lame. When the Cursor Mundi was written, lame had an even wider application, meaning disabled in any part of the body, not merely the legs.
Over time, halt and lame became a set phrase similar to other repetitive expressions that combined words of similar application such as kith and kin and time and tide (in the latter, tide means a season or a moment in time, as in eventide). The link was helped along by the gradual shift of lame to refer exclusively to the legs.