אור החיים — צו את אהרן ואת בניו לאמר

Q — What does the word 'לאמר' ('saying') add in 'Command Aharon and his sons saying' — to whom are Aharon and his sons being told to speak?

A — Or HaChaim offers that 'לאמר' does not refer to what Aharon must say to others, but to what Moshe must say to Aharon: he must convey not merely the bare verses but the oral expositions encoded in them ('דרשות הרמוזות במכתב אלהים') and the precise inferences the text intends. Since 'the verse is like a sealed vision' (כחזון הסתום), Aharon could not have known the laws from the words alone. The detailed halachot given to Moshe at Sinai — which are the very derashot Chazal expound — these God commanded him to transmit to Aharon. A striking statement that the Oral Law's halachot were given as tradition and only anchored to the verses.