During saponification hydroxide ions from the lye join to the triglyceride to form glycerol, and the sodium bonds with the fatty acids making the soap molecules. However, it is sometimes the case that $NaCl$ is needed at this point to precipitate out the soap. The sodium ions are used in this precipitation. But, what happens to the excess chloride ions?
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Adding a concentrated $\ce{NaCl}$ solution to a soap solution produces the precipitation of sodium alkanoates (indeed it is a mixture of alkanoates and alkenoates). This is a consequence of the law of mass action. The ions $\ce{Cl-}$ and $\ce{Na+}$ added in this operation remain in solution. The only products to precipitate are the sodium alkanoates which were present in the solution before adding $\ce{NaCl}$
