مَا رُطَيْنَاكَ

and رُطَّيْنَاكَ means مَا الذَّى تَرْطُنُ بِهِ [i. e. What is that to which thou alludest, not mentioning it explicitly?]: (JM:) or مَا رُطَّيْنَاكَ هٰذِهِ, and sometimes without teshdeed, means What is [this] thy speech? (K.)