﴿ فَتَنَٰزَعُوٓا۟ أَمْرَهُم بَيْنَهُمْ وَأَسَرُّوا۟ ٱلنَّجْوَىٰ ﴾

“So they debated among themselves as to what to do; but they kept their counsel secret,”

So they disputed their matter among themselves regarding Moses and his brother and kept secret their private counsel that is their conversation regarding the two