If the distance between the plane, 23x – 10y – 2z + 48 = 0 and the plane

containing the lines ${{x + 1} \over 2} = {{y - 3} \over 4} = {{z + 1} \over 3}$

and ${{x + 3} \over 2} = {{y + 2} \over 6} = {{z - 1} \over \lambda }\left( {\lambda \in R} \right)$

is equal to ${k \over {\sqrt {633} }}$, then k is equal to ______.