This question already has an answer here:
There are numerous places in the Torah (as well as the rest of Tanac"h) that have ktiv / kri conflicts. The word is written one way but pronounced differently.
For example, Numbers 1:16:
אֵ֚לֶּה קריאי [קְרוּאֵ֣י] הָעֵדָ֔ה נְשִׂיאֵ֖י מַטּ֣וֹת אֲבוֹתָ֑ם רָאשֵׁ֛י אַלְפֵ֥י יִשְׂרָאֵ֖ל הֵֽם׃
These were the elect of the congregation, the princes of the tribes of their fathers; they were the heads of the thousands of Israel.
(I've left the English translation for M.Y. reader's info)
In the above sample, the bold word is how it is written in the Torah, and the bracketed word is how it is read.
I assume that when Moses wrote the Torah, G-d communicated each word that Moshe was supposed to write them down. I think it's safe to assume that Moshe knew how to spell Hebrew words (and while he did have speech problems, his hearing was fine ;-) So, when it came to kri / ktiv situations such as the one above, did G-d say, "No, Moshe. I want you to write the word THIS way, but you'll tell everyone that it really is supposed to be said THAT way?" How did these conflicts originate, and what was the purpose of having them? Why not make it consistent to start?
(I'm uncertain of how to tag this question.)