Or HaChaim on Exodus 16:9/אור החיים על שמות ט״ז:ט׳

1 ויאמר משה אל אהרון, Moses said to Aaron, etc. It is possible that Moses spoke this verse on the first day when he said to the people that they would recognise that it was G'd who had taken them out of Egypt and not he or Aaron. It is also possible that Moses spoke to Aaron only on the following day and that the reference to "evening" in verse 6 did not refer to the evening of that day, but to the evening following provision of the quail; in that case Moses refrained from mentioning what happened in the morning.