Charles H. Spurgeon on Psalms 95:9

Forty years. To understand this passage we must bear in mind the event referred to. The same year in which the people of Israel came forth from Egypt, they were distressed for water at Rephidim, (Ex 17:1); and the place had two names given to it, Massah and Meribah, because the people tempted God and chided with Moses. The Lord did not swear then that they should not enter into the land of Canaan; but this was in the following year, after the return of the spies. (Nu 14:20-38.) And God said then that they had tempted him "ten times"; that is, during the short time since their deliverance from Egypt. It was after ten temptations that God deprived them of the promised land. Bearing in mind these facts, we shall be able to see the full force of the passage. The "provocation" or contention, and "temptation" refer clearly to the latter instance, as recorded in Nu 14:1-45 because it was then that God swore that the people should not enter into his rest. The people's conduct was alike in both instances. To connect "forty years" with grieved, was the work of the Punctuists, and this mistake the Apostle corrected; and it is to be observed that he did not follow in this instance the Septuagint, in which the words are arranged as divided by the Masorites. Such a rendering as would correspond with the Hebrew is as follows, —

"Today when ye hear his voice,

8. Harden not your hearts us in the provocation, In the day of temptation in the wilderness.

9. When your fathers tempted me, they proved me And saw my works forty years: 10. I was therefore offended with that generation and said, Always do they go astray in heart, And they have not known my ways; 11. So that I swore in my wrath, `They shall by no means enter into my rest.'"

The meaning of the ninth verse is, that when the children of Israel tempted God, they proved him, i.e., found out by bitter experience how great his displeasure was, and saw his works or his dealings with them forty years. He retained them in the wilderness during that period until the death of all who disbelieved his word at the return of the spies; he gave them this proof of his displeasure. —John Owen, of Thrussington, 1853.