John Calvin Commentary Hebrews 3:9

"Where your fathers tried [me] by proving [me,] And saw my works forty years." — Hebrews 3:9 (ASV)

Tempted, etc. This word should be understood in a bad sense; it means to provoke in a proud and insulting manner, which we express in French by saying, defier comme en depitant. For though God had often brought them help, they still forgot everything and scornfully asked, "Where was his power?"

Proved, etc. This clause should be explained as follows: When yet they had proved me and seen my works. For it increased the guilt of their impiety that, having been taught by so many evidences of divine power, they had made such poor progress. Indeed, it was an astonishing apathy and stupidity to regard God’s power as nothing, which had been so fully proved.

Forty years. These are connected by David with what follows. But we know that the Apostles, in quoting passages, pay more attention to the general meaning than to the specific words. And, no doubt, God complained that the people had been troublesome to him for forty years, because so many benefits had no effect in teaching them. For though God continually did good to those who were entirely unworthy, they yet never ceased to rise up against him.

Hence arose his continual indignation, as though he had said, “Not once or for a short time have they provoked me, but by their incessant wickedness for forty years.” Generation means a race, or people of one age.