'Opportunity' in the Bible

Therefore, since the promise remains for some to enter His rest, and those who formerly had the good news preached to them failed to [grasp it and did not] enter because of [their unbelief evidenced by] disobedience,

He again sets a definite day, [a new] “Today,” [providing another opportunity to enter that rest by] saying through David after so long a time, just as has been said before [in the words already quoted],“Today if you hear His voice,Do not harden your hearts.”

And if they had been thinking of that country from which they departed [as their true home], they would have had [a continuing] opportunity to return.

For you know that later on, when he wanted [to regain title to] his inheritance of the blessing, he was rejected, for he found no opportunity for repentance [there was no way to repair what he had done, no chance to recall the choice he had made], even though he sought for it with [bitter] tears.