Charles Ellicott Commentary Deuteronomy 1:46

"So ye abode in Kadesh many days, according unto the days that ye abode [there]." — Deuteronomy 1:46 (ASV)

So you stayed in Kadesh many days. —Better, and. In Numbers 14:25 the command was, “Tomorrow turn you, and get you into the wilderness.” This command was broken by the attack on the Canaanites, made on the next day after the command. We cannot be certain that the many days spent in Kadesh were spent after the defeat. It may be merely a note of the fact that the time spent in Kadesh was considerable. The mission of the spies alone occupied forty days.

According to the days that you stayed there. —The Jewish commentator Rashi, quoting from Sêder Olâm, says they were in Kadesh, and nineteen in their wanderings.