Surah Al-Ahzab (33): Verse 19
{أَشِحَّةً عَلَيْكُمْ} (Stingy toward you)
This points to the extreme degree of their cowardice and intense fear.
Know that stinginess (miserliness) is akin to cowardice. Since the text mentioned stinginess, it clarified its cause, which is cowardice. What indicates this is that the coward is stingy with his wealth and does not spend it in the cause of Allah because he does not expect victory or hope for spoils. He thinks, "This expenditure has no equivalent return," so he hesitates.
However, the courageous person is certain of victory and gain, making it easy for him to spend wealth in battle, hoping for a return many times greater.
Similarly, regarding life and body: the coward fears his opponent and imagines failure, so he becomes timid and refrains from advancing. The courageous person, however, is confident of overcoming and triumphing, so he advances.
{فَإِذَا ذَهَبَ الْخَوْفُ سَلَقُوكُمْ} (But when the fear departs, they will smite you)
This means they will overcome you with their tongues and harm you with their words, claiming, "We are the ones who fought, and because of us you were victorious and broke the enemy." They will then demand the larger share of the spoils, whereas before, they were content with merely returning safely.
{أَشِحَّةً عَلَى الْخَيْرِ} (Stingy about the good)
It is said that "the good" refers to wealth. It can also be interpreted to mean that they are deficient in good in both situations and abundant in evil in both times: first, they are stingy, and second, they are similarly so (by attacking the believers with words).
{أُولَئِكَ لَمْ يُؤْمِنُوا فَأَحْبَطَ اللَّهُ أَعْمَالَهُمْ وَكَانَ ذَلِكَ عَلَى اللَّهِ يَسِيرًا} (Those are the ones who have not believed, so Allah has nullified their deeds. And that has been easy for Allah.)
This means they have not truly believed, even if they verbally professed faith. Therefore, Allah nullified the deeds they used to perform alongside the Muslims.
His statement {وَكَانَ ذَلِكَ عَلَى اللَّهِ يَسِيرًا} (And that has been easy for Allah) refers to what appears to the observer, similar to His saying: {وَهُوَ أَهْوَنُ عَلَيْهِ} (And that is easier for Him) [Ar-Rum: 27].
This is because nullification (Iḥbāṭ) is annihilation and rendering void. When one observes the annihilation of physical bodies, they see the body dispersed by the separation of its parts. If someone burns something, ash remains. If the wind scatters that ash, particles remain—this is the view of some people.
The correct view is that Allah annihilates physical bodies and recreates whatever He wills from them. As for deeds, they are annihilated in essence, even if their effect or trace remains. If a deed has no benefit or consideration, it is truly and legally non-existent. Thus, a deed, if disregarded, is non-existent in reality, unlike a physical body.
Surah Al-Ahzab (33): Verses 20-21
{يَحْسَبُونَ الْأَحْزَابَ لَمْ يَذْهَبُوا وَإِنْ يَأْتِ الْأَحْزَابُ يَوَدُّوا لَوْ أَنَّهُمْ بَادُونَ فِي الْأَعْرَابِ يَسْأَلُونَ عَنْ أَنْبَائِكُمْ وَلَوْ كَانُوا فِيكُمْ مَا قَاتَلُوا إِلَّا قَلِيلًا * لَقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ أُسْوَةٌ حَسَنَةٌ لِمَنْ كَانَ يَرْجُو اللَّهَ وَالْيَوْمَ الْآخِرَ وَذَكَرَ اللَّهَ كَثِيرًا}
(20) They think the Confederates have not withdrawn. And if the Confederates should come, they would wish they were out in the desert among the Bedouins, asking for news about you. And if they were among you, they would fight little.
(21) Indeed, in the Messenger of Allah you have an excellent example for whoever would hope for Allah and the Last Day and remember Allah often.