Hashem asked Moshe Rabeinu to “please” ask the Yidden, that they should “please” ask their Egyptian neighbors for their gold and silver. (Berachos 9a) Hashem said to Moshe, “Please, go and say to the Yidden, please ask from the Mitzrim vessels of silver and gold, so that Avraham Avinu should not say, ‘You fulfilled the part of the prophecy that they will be enslaved and afflicted, but not the part that they will leave with great wealth.’”
Shaarim B’Tefillah (R’ Shimshon Dovid Pincus) explains: One of the great rules in Hashgacha is that even though Hashem sees everything and knows all, He set up the world so that, as it were, He “doesn’t see” what isn’t shown to Him, and “doesn’t know” what isn’t brought to His attention. This is a foundation for Bechirah and Tzelem Elokim. Even if a person is in great trouble, if he doesn’t express it to Hashem, it’s as if Hashem doesn’t “see” or “hear” it. Only when a person cries out does Hashem “hear” and respond, like a merciful father who is moved by his child’s cries. All the gates are locked except the gates of tears (Bava Metzia 59a). If you don’t tell Hashem what hurts, it’s as if He doesn’t know. The Torah says: ה' שִמְעָה בְקוֹלִי תִהְיֶינָה אָזְנֶיךָ קַשֻבוֹת לְקוֹל תַחֲנוּנָי (Tehillim 130:2)—Hashem “listens” with “ears,” not with Ruach HaKodesh. If you don’t tell Him, as it were, He doesn’t know. This is how Hashgacha works.
