Numbers 32:13

And the Lord's anger was kindled against Israel
For murmuring against the report of the spies:

and he made them wander in the wilderness forty years;
for though it was but about thirty eight years from that time that they were in the wilderness, the round number of forty is given; and besides it includes the time of their first coming into it, which being reckoned, makes the complete number, within a few months: Kadesh, from whence the spies were sent, and whither they returned, and where the people murmured, and had this sentence pronounced on them, that they should not see the land of Canaan, but wander and fall in the wilderness, seems to have had the addition of Barnea made unto it on that account, which signifies the son of him that wandereth:

until all the generation which had done evil in the sight of the Lord
was consumed;
as they all were at this time when Moses spake these words.