St Paul takes this expression, "they tempted," from the circumstance of which the prophet speaks, and transfers it to the occasion when the Israelites faintheartedly complained about the scarcity of food. Strictly speaking, that was murmuring.
Thus here too the matter concerns food. The speech of the murmurers is also the same: "Can God?" only with greater doubt.
By the words "let us not tempt Christ," the Apostle hints that the Corinthians were somehow guilty of this. Yet exactly how cannot be shown with certainty from the epistle.
Oecumenius writes that they tempted Christ by demanding signs. Perhaps such an incident occurred during the first preaching. With such an extraordinary faith, signs were necessary, and the Apostles were armed with them.
Yet this demand was so natural that it cannot fully be called a tempting of the Lord.
St Chrysostom says that "the Apostle here points to yet another transgression, accusing the Corinthians of murmuring against trials and saying: 'When will the good things come? When will the rewards come?'"
It is very likely that in these two verses, "let us not tempt" and "do not murmur," the Apostle hints at the Corinthians' faintheartedness, against which he later encourages them (verse 13).
But there is no need to seek precision, because the Apostle's purpose in citing these examples is only this: to impress that one cannot live without caution merely because one has been called and baptized.
This is clear also from examples whose application is understandable. Some offer yet another thought: to tempt the Lord means to throw oneself into dangers with the curious thought, "I shall see whether God will deliver me."
Those who ate idol-sacrifices exposed themselves to various moral temptations. Perhaps they thought: the Lord will deliver us, or, let us see whether Christ will deliver us when danger approaches.
Therefore the Apostle says to them: let us not tempt Christ.