"And Moses said to them: Why do you quarrel with me?" (Exodus 17:2). He said to them: As long as you keep disputing with me, you are putting the Omnipresent to the test, as it is said, "Why do you test the LORD?" (Exodus 17:2).
When You Quarrel With Moses You Are Testing the Lord
Yalkut Shimoni on Torah 261:15
וַיֹּאמֶר לָהֶם מֹשֶׁה מַה תְּרִיבוּן עִמָּדִי. אָמַר לָהֶם, כָּל זְמַן שֶׁאַתֶּם מִדַּיְּנִים עִמָּדִי אַתֶּם מְנַסִים לַמָּקוֹם, שֶׁנֶּאֱמַר מַה תְּנַסּוּן אֶת ה'.