He knows the hidden thought and the spoken word alike.
No gap between private and public for Allah
The surah turns from gifts to the idols people called on. First it reminds them: Allah knows what is hidden in hearts as well as what is apparent. Ibn Kathir adds that everyone will be rewarded or punished for their deeds on the Day of Resurrection.
You smile in the meeting while typing a different message under the table. You post a kind caption about someone you resent. The audience only sees one side. He sees both, and He is the only audience that lasts.
What I keep inside is my own business.
My hidden side is as open to Allah as my public face.
Pick one thing you say in public and check today whether your heart matches it.