Ezekiel is summarizing all of their disobedience, but the specific act that kept Israel from inheriting the land was their refusal to enter the land when he told them to (Exodus 14).
They disobeyed other things too, but God was very specific in singling out breaking the Sabbath and relates breaking the Sabbath to idol worship. Replacing what God said, with a voice of another. Why the commandments are all interconnected breaking one we break them all James2:11.
Eze20:16
because they rejected my rules and did not walk in my statutes,
and profaned my Sabbaths; for their heart went after their idols.
Eze 20:13 13 Yet the house of Israel
rebelled against Me in the wilderness; they did not walk in My statutes; they despised My judgments, ‘which,
if a man does, he shall live by them’;
and they greatly defiled My Sabbaths. Then I said I would pour out My fury on them in the wilderness, to consume them.
Jesus called breaking the Sabbath rebellion.
What we are called not to follow....
Heb 3:7 Therefore, as the Holy Spirit says:
“Today, if you will hear His voice,
8
Do not harden your hearts as in the rebellion,
In the day of trial in the wilderness,
9 Where your fathers tested Me, tried Me,
And saw My works forty years.
10 Therefore I was angry with that generation,
And said, ‘They always go astray in
their heart,
And they have not known My ways.’
11 So I swore in My wrath,
‘They shall not enter My rest.’ ”
12 Beware, brethren, lest there be in any of you an evil heart of unbelief in departing from the living God; 13 but [
b]exhort one another daily, while it is called “Today,” lest any of you be hardened through the deceitfulness of sin. 14 For we have become partakers of Christ if we hold the beginning of our confidence steadfast to the end, 15 while it is said:
“Today, if you will hear His voice,
Do not harden your hearts as in the rebellion.”
16 For who, having heard, rebelled? Indeed,
was it not all who came out of Egypt,
led by Moses? 17 Now with whom was He angry forty years?
Was it not with those who sinned, whose corpses fell in the wilderness? 18 And to whom did He swear that they would not enter His rest, but to those who did not obey? 19 So we see that they could not enter in because of unbelief.