"They [seek to] deceive Allah and those who believe," so that they may be spared from their blood, their wealth, and the enslavement of their offspring. Their deception of the Messenger of Allah and the believers is a deception of Allah. "But they deceive not except themselves," meaning that the torment for it and the recompense for their disbelief return upon them, "and they perceive [it] not," that this is returning upon them.
﴿يخادعون الله وَالَّذين آمنُوا﴾ حَتَّى يكفوا عَنْ دِمَائِهِمْ وَأَمْوَالهمْ. وَسبي ذَرَارِيهمْ، ومُخَادَعَتُهُمْ لرَسُول اللَّه وَلِلْمُؤْمنِينَ مخادعة لله ﴿وَمَا يُخَادِعُونَ إِلا أَنْفُسَهُمْ﴾ أَي أَن ذَلِك يرجع عَلَيْهِم عَذَابه، وثواب كفره ﴿وَمَا يَشْعُرُونَ﴾ أَن ذَلِك رَاجع عَلَيْهِم.