We should realize that someone may read this argument as saying "the ruling in 8:65 is no longer valid while the verse remains as an important historical fact," and may view this as precisely what abrogation means. We need to face this specific logic head on.
I acknowledge that many would say that's what abrogation is, but I respectfully disagree. To my mind, these two examples here are examples of one command ending and another beginning. Abrogation, on the other hand, is one command interrupted
and modified. This may sound like splitting hairs and I acknowledge that the distinction may escape many.
When you refer to the battle of Badr, do you know of timing information or other circumstantial evidence that can support that? Was there a time lapse between the revelations of 8:65 and 8:66? The smaller number of Muslims in 8:65 would suggest that, but I wonder if there is stronger evidence.
This is what Al-Qurtubi writes about 8:66 in his exegesis,
قال ابن العربي: قال قوم إن هذا كان يوم بدر ونسخ. وهذا خطأ من قائله. ولم ينقل قط أن المشركين صافوا المسلمين عليها، ولكن الباري جل وعز فرض ذلك عليهم أولا، وعلق ذلك بأنكم تفقهون ما تقاتلون عليه، وهو الثواب. وهم لا يعلمون ما يقاتلون عليه. قلت: وحديث ابن عباس يدل على أن ذلك فرض. ثم لما شق ذلك عليهم حط الفرض إلى ثبوت الواحد للاثنين، فخفف عنهم وكتب عليهم ألا يفر مائة من مائتين، فهو على هذا القول تخفيف لا نسخ. وهذا حسن. وقد ذكر القاضي ابن الطيب أن الحكم إذا نسخ بعضه أو بعض أوصافه، أو غير عدده فجائز أن يقال إنه نسخ، لأنه حينئذ ليس بالأول، بل هو غيره. وذكر في ذلك خلافا
So, Al-Qurtubi sees no abrogation here, but an easing of requirement. Ibn At-Tayyib seems to agree though he says this may
be called abrogation.
Another point along the same lines. In the case of 73:20, the counterargument against abrogation is that the command in 73:1-4 was explicitly confined to the Prophet (PBUH). Is it possible that in 8:65 there is a similar confinement? The opening of 8:65 is an indication that the command is through the Prophet "O Prophet, urge the believers to battle" while 8:66 is a direct command from God. What are the implications of that?
I'd agree because the addressed in 8:65 is the Prophet, but the addressed in 8:66 are the believers.
You bring up a point I've been meaning to discuss. The only command in 8:65 is for the Prophet (PBUH) to urge the believers to fight. Was that command
abrogated by 8:66 or any other verse? That would mean that the Prophet never again had to urge the believers to fight. Is that a historical fact?
What I see is that what was modified was the argument
the Prophet may use to persuade the believers. Thus, no abrogation occurred here because no command was modified. Is that splitting hairs too?
A final possibility is the revival of the question of whether 8:65 could be a statement of fact, especially because of the closing of the verse "because they are a folk who do not comprehend." Without the opening of 8:66, "Now, God has lightened [the hardship] on you," the argument about a statement of fact is easy to make, so could it be that 8:65 is a statement of fact and 8:66 is a command?
I actually see the opposite, as I explained above. 8:65 is the verse that has the command while 8:66 has no command. The closing clause of 8:65 simply elaborates why the one-to-ten ratio will work. Earlier in the chapter, God gives the believers the good news that He will supply them with angels to fight alongside them, responding favorably to their plea for help,