Allah knows the fraud of the eyes, and all that the breasts conceal.
Allah tells us about His complete knowledge which encompasses all things, great and small, major and minor, so that people will take note that. He knows about them and they will have the proper sense of shyness before Allah. They will pay attention to the fact that He can see them, for He knows the fraud of the eyes, even if the eyes look innocent, and He knows what the hearts conceal.
Ad-Dahhak said;
خَايِنَةَ الاْاَعْيُنِ
(the fraud of the eyes),
"A wink and a man saying that he has seen something when he has not seen it, or saying that he has not seen it when he did see it."
Ibn Abbas, may Allah be pleased with him, said,
"Allah knows when the eye looks at something, whether it wants to commit an act of betrayal or not."
This was also the view of Mujahid and Qatadah.
Ibn Abbas, may Allah be pleased with him, commented on the Ayah;
وَمَا تُخْفِي الصُّدُورُ
(and all that the breasts conceal).
"He knows, if you were able to, whether you would commit Zina with a woman or not."
As-Suddi said;
وَمَا تُخْفِي الصُّدُورُ
(and all that the breasts conceal).
meaning, of insinuating whispers