Is it קרי or בקרי?
(26,21) “And if you go with Me casually (קרי)…”
The Mesorah on this posuk says that the first and second are קרי, the third and fourth are בקרי, the fifth is קרי, and the sixth and seventh are בקרי. And this is how it is determined - when there is את קרי, and when there is ואת בקרי. What the Mesorah writes here is a puzzle.
But we can explain that the Mesorah is referring to the posuk in Melachim Ⅰ 8:64 “On that day the king sanctified…”, and is using that posuk as an aid to remember whether it should write here קרי or בקרי, because in that posuk the word את is written seven times and in our posukim the word קרי is also written seven times. Thus this is what the Mesorah is saying: corresponding to where the word את is written over there, here the word קרי is written, and corresponding to where it writes ואת, here it writes בקרי.