What is meant by "they deceive Allah"?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. They were deceiving the believers, so it is as if they sought to deceive Allāh. [Ibn ʿAbbās, Ibn Qutaybah]
2. They sought to deceive the Prophet of Allah (ﷺ), so Allāh spoke of the Prophet (ﷺ) in the position of his Lord, just like He said, "Indeed, those who pledge allegiance to you (O Muḥammad), they are actually pledging allegiance to Allāh" (48:10). [Al-Zajjāj]
3. "Khādiʿ" in the Arabic language means corrupt, so the verse means that they spoil the faith which they display outwardly with their hidden disbelief. [Ibn al-Anbārī]
4. Their behavior towards Allāh's religion would be called "deception" if they treated each other that way.
5. They used to hide their disbelief while making an outward show of faith.