Exodus 15:25

[25] And he cried to the LORD, and the LORD showed him a log, and he threw it into the water, and the water became sweet.

There the LORD made for them a statute and a rule, and there he tested them, (ESV)

Exodus 16:4

[4] Then the LORD said to Moses, “Behold, I am about to rain bread from heaven for you, and the people shall go out and gather a day’s portion every day, that I may test them, whether they will walk in my law or not. (ESV)

Exodus 17:7

[7] And he called the name of the place Massah and Meribah, because of the quarreling of the people of Israel, and because they tested the LORD by saying, “Is the LORD among us or not?” (ESV)