«وَالْتَفَّتِ السَّاقُ بِالسَّاقِ ... إِلَى رَبِّكَ يَوْمَئِذٍ الْمَسَاقُ»
The leg is entwined with the leg ... on that day the driving is toward your Lord.
Relative to «الساق», «المساق» retains a recognizable sound sequence while adding a mīm. The meanings are also distinct: the first evokes the physical leg, the second the act or destination of being driven.
The similar sounds help bind the solemn scene, but the different number of letters rules out complete jinās. The meaningful connection in the verse is as important as the audible echo.