The Qur'an was told to Muhammad PBUH by an angel, who says that they do not ever disobey Allah swt.
O you who have believed, protect yourselves and your families from a Fire whose fuel is people and stones, over which are [appointed] angels, harsh and severe; they do not disobey Allah in what He commands them but do what they are commanded.
This is different from saying that angels have no free will, which requires that they be unable to disobey Allah swt. We know they have more complete information about Allah than humanity, and we know they are aware that there is nothing greater than serving Allah swt.
Allah witnesses that there is no deity except Him, and [so do] the angels and those of knowledge - [that He is] maintaining [creation] in justice. There is no deity except Him, the Exalted in Might, the Wise.
Normative ethics is the branch of philosophy concerned with how people should act, morally speaking. Consider these three ethical positions:
Agent-centered deontological ethics - Allah swt commands, so the angels obey.
An agent-relative reason is so-called because it is a reason relative to the agent whose reason it is; it need not (although it may) constitute a reason for anyone else. Thus, an agent-relative obligation is an obligation for a particular agent to take or refrain from taking some action; and because it is agent-relative, the obligation does not necessarily give anyone else a reason to support that action.
Consequentialism - Obeying Allah swt is the greatest good, which angels know, while disobedience is clearly worse.
The paradigm case of consequentialism is utilitarianism. ... Classic utilitarians held hedonistic act consequentialism. Act consequentialism is the claim that an act is morally right if and only if that act maximizes the good, that is, if and only if the total amount of good for all minus the total amount of bad for all is greater than this net amount for any incompatible act available to the agent on that occasion. ... Hedonism then claims that pleasure is the only intrinsic good and that pain is the only intrinsic bad. Together these claims imply that an act is morally right if and only if that act causes “the greatest happiness for the greatest number,” as the common slogan says.
Virtue ethics - From Surah 21:19-20, we know that the angels are always exalting Allah swt.
A virtue such as honesty or generosity is not just a tendency to do what is honest or generous, nor is it to be helpfully specified as a “desirable” or “morally valuable” character trait. It is, indeed a character trait—that is, a disposition which is well entrenched in its possessor, something that, as we say “goes all the way down”, unlike a habit such as being a tea-drinker—but the disposition in question, far from being a single track disposition to do honest actions, or even honest actions for certain reasons, is multi-track. It is concerned with many other actions as well, with emotions and emotional reactions, choices, values, desires, perceptions, attitudes, interests, expectations and sensibilities.
Therefore, it appears that the behavior of angels can be regarded as a perfect application of ethical principles, rather than a full denying of free will.
Has the distinction between perfect ethical behavior and a literal lack of free will with regards to angels been discussed, and if so, where?
I am interested in Islamic scholarly sources.