the meaning of the phrase “they (think to) deceive Allaah” in the aayah from Soorat al-Baqarah

Ibn Katheer said in his tafseer of this aayah:

“ ‘they (think to) deceive Allaah and those who believe’ [al-Baqarah 2:9 – interpretation of the meaning] means, by their making an outward show of faith whilst inwardly they conceal kufr. They think in their ignorance that they can deceive Allaah in this way, and that this will benefit them with Him. They think that they can fool Him as they fooled some of the believers, as Allaah says (interpretation of the meaning):
“On the Day when Allaah will resurrect them all together (for their account); then they will swear to Him as they swear to you (O Muslims). And they think that they have something (to stand upon). Verily, they are liars!” [al-Mujaadilah 58:18]
Hence Allaah responds to their belief by saying (interpretation of the meaning):
“while they only deceive themselves, and perceive (it) not!”
[al-Baqarah 2:9]
i.e., they are not deceiving anyone by their actions but themselves, but they do not perceive that in themselves. This is like the aayah (interpretation of the meaning):
“Verily, the hypocrites seek to deceive Allaah, but it is He Who deceives them” [al-Nisaa’ 4:142]
We advise the American who wants to learn about Islam to be fair-minded and free from whims and desires. He should beware of the ways in which the enemies of Islam try to distort Islam. He should strive to learn about Islam from its pure sources and not from the sects who give a bad image of Islam by their bid’ah and innovations, like the Qadiaanis (Ahmadis), Shi’ah and Sufis, etc. These groups have distorted the message of Islam with their innovations, so he should not regard their actions and words as being Islam. We ask Allaah to guide him.

Shaykh Sa’d al-Humayd