“The Lord tests the righteous, but He hates the wicked and the lover of injustice” (Psalms 11:5) – Rabbi Yonatan said: A linen producer, when his flax is inferior, he does not beat it extensively because it would break, but when his flax is of high quality, he beats it exceedingly, because it continually improves [through this process]. So, the Holy One blessed be He does not test the wicked. Why?
Because they would be unable to withstand it, as it is written: “But the wicked are like the stormy sea” (Isaiah 57:20).3When the wicked suffer they lash out against God. Whom does He test? It is the righteous, as it is stated: “The Lord tests the righteous,” [such as in this incident:] “It was after these matters that his master's wife [cast her eyes upon Joseph]” (Genesis 39:7). “It was after these matters” – Rabbi Yonatan said: A potter, when he wants to evaluate [the products of] his kiln, he does not test the fragile vessels.
Why? It is because he would not be able to knock on one of them even once without breaking it. What does he test? The sturdy vessels, as even if he knocks on one of them several times, he will not break it.
So, the Holy One blessed be He does not test the wicked, but rather, the righteous, as it is stated: “The Lord tests the righteous.” Rabbi Elazar said: This is analogous to a homeowner who had two cows, one strong and one feeble. Upon which one does he place the yoke? Is it not upon the one that is strong? So, the Holy One blessed be He tests only the righteous, as it is stated: “The Lord tests the righteous.”