Well, He meant the other commands as non negotiables. Very few direct commands are actually given in the Bible. Why would “Thou shall not kill,” “Thou shall not steal” and “Thou shall love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind” and “Thou shall love thy neighbor as thyself” and “Amen, amen, I say to you, whoever receives the one I send receives me, and whoever receives me receives the one who sent me” count, but not the very first command.
Oh look at that, the last quote I listed is quite fitting as well. Maybe the fact that it is confirmed by the Son makes the command from the Father even more important to obey.