Allah declares that His knowledge is encompassing all of His creation, those who declare their speech or hide it, He hears it and nothing of it ever escapes His observation. Allah said in other Ayat,

﴿ظˆظژط¥ظگظ† طھظژط¬ظ’ظ‡ظژط±ظ’ ط¨ظگط§ظ„ظ’ظ‚ظژظˆظ’ظ„ظگ ظپظژط¥ظگظ†ظ‘ظژظ‡ظڈ ظٹظژط¹ظ’ظ„ظژظ…ظڈ ط§ظ„ط³ظ‘ظگط±ظ‘ظژ ظˆظژط£ظژط®ظ’ظپظژظ‰ ﴾

(And if you speak aloud, then verily, He knows the secret and that which is yet more hidden.)﴿20:7﴾, and,

﴿ظˆظژظٹظژط¹ظ’ظ„ظژظ…ظڈ ظ…ظژط§ طھظڈط®ظ’ظپظڈظˆظ†ظژ ظˆظژظ…ظژط§ طھظڈط¹ظ’ظ„ظگظ†ظڈظˆظ†ظژ﴾

(And (Allah) knows what you conceal and what you reveal.) `A'ishah said, "All praise is due to Allah Whose hearing has encompassed all voices! By Allah, she who came to complain about her husband to the Messenger of Allah was speaking while I was in another part of the room, yet I did not hear some of what she said. Allah sent down,

﴿ظ‚ظژط¯ظ’ ط³ظژظ…ظگط¹ظژ ط§ظ„ظ„ظ‘ظژظ‡ظڈ ظ‚ظژظˆظ’ظ„ظژ ط§ظ„ظ‘ظژطھظگظ‰ طھظڈط¬ظژط§ط¯ظگظ„ظڈظƒظژ ظپظگظ‰ ط²ظژظˆظ’ط¬ظگظ‡ظژط§ ظˆظژطھظژط´ظ’طھظژظƒظگظ‰ ط¥ظگظ„ظژظ‰ ط§ظ„ظ„ظ‘ظژظ‡ظگ ظˆظژط§ظ„ظ„ظ‘ظژظ‡ظڈ ظٹظژط³ظ’ظ…ظژط¹ظڈ طھظژط­ظژط§ظˆظڈط±ظژظƒظڈظ…ط¢ ط¥ظگظ†ظ‘ظژ ط§ظ„ظ„ظ‘ظژظ‡ظژ ط³ظژظ…ظگظٹط¹ظŒ ط¨ظژطµظگظٹط±ظŒ ﴾

(Indeed Allah has heard the statement of her that disputes with you concerning her husband and complains to Allah. And Allah hears the argument between you both. Verily, Allah is All-Hearer, All-Seer.)﴿58:1﴾ Allah said next,

﴿ظˆظژظ…ظژظ†ظ’ ظ‡ظڈظˆظژ ظ…ظڈط³ظ’طھظژط®ظ’ظپظچ ط¨ظگط§ظ„ظ‘ظژظٹظ’ظ„ظگ﴾

(whether he be hid by night), in his house in the darkness of the night,

﴿ظˆظژط³ظژط§ط±ظگط¨ظŒ ط¨ظگط§ظ„ظ†ظ‘ظژظ‡ظژط§ط±ظگ﴾

(or goes forth freely by day.) moves about during the daylight; both are encompassed by Allah's knowledge. Allah said in other Ayat,

﴿ط£ظژظ„ط§ ط­ظگظٹظ†ظژ ظٹظژط³ظ’طھظژط؛ظ’ط´ظڈظˆظ†ظژ ط«ظگظٹظژط§ط¨ظژظ‡ظڈظ…ظ’﴾

(Surely, even when they cover themselves with their garments.) ﴿11:5﴾, and,

﴿ظˆظژظ…ظژط§ طھظژظƒظڈظˆظ†ظڈ ظپظگظ‰ ط´ظژط£ظ’ظ†ظچ ظˆظژظ…ظژط§ طھظژطھظ’ظ„ظڈظˆط§ظ’ ظ…ظگظ†ظ’ظ‡ظڈ ظ…ظگظ† ظ‚ظڈط±ظ’ط،ظژط§ظ†ظچ ظˆظژظ„ط§ظژ طھظژط¹ظ’ظ…ظژظ„ظڈظˆظ†ظژ ظ…ظگظ†ظ’ ط¹ظژظ…ظژظ„ظچ ط¥ظگظ„ط§ظ‘ظژ ظƒظڈظ†ظ‘ظژط§ ط¹ظژظ„ظژظٹظ’ظƒظڈظ…ظ’ ط´ظڈظ‡ظڈظˆط¯ظ‹ط§ ط¥ظگط°ظ’ طھظڈظپظگظٹط¶ظڈظˆظ†ظژ ظپظگظٹظ‡ظگ ظˆظژظ…ظژط§ ظٹظژط¹ظ’ط²ظڈط¨ظڈ ط¹ظژظ† ط±ظ‘ظژط¨ظ‘ظگظƒظژ ظ…ظگظ† ظ…ظ‘ظگط«ظ’ظ‚ظژط§ظ„ظگ ط°ظژط±ظ‘ظژط©ظچ ظپظگظٹ ط§ظ„ط§ظ‘ظŒط±ظ’ط¶ظگ ظˆظژظ„ط§ظژ ظپظگظ‰ ط§ظ„ط³ظ‘ظژظ…ظژط¢ط،ظگ ظˆظژظ„ط§ظژ ط£ظژطµظ’ط؛ظژط±ظژ ظ…ظگظ† ط°ظژظ„ظگظƒظژ ظˆظژظ„ط§ ط£ظژظƒظ’ط¨ظژط±ظژ ط¥ظگظ„ط§ظ‘ظژ ظپظگظ‰ ظƒظگطھظژط§ط¨ظچ ظ…ظ‘ظڈط¨ظگظٹظ†ظچ ﴾

(Neither you do any deed nor recite any portion of the Qur'an nor you do any deed, but We are witness thereof when you are doing it. And nothing is hidden from your Lord (so much as) the a speck of dust on the earth or in the heaven. Not what is less than that or what is greater than that but is (written) in a Clear Record.)﴿10:61﴾