So is there an explicit statement for anything like this? What is the general view on murder? Thank you in advance.
"Murder" is "unlawful killing" (plus sometimes some additional requirement, often something like it was premeditated, or that you had very bad reasons for the killing, for example as a hitman) in every system of law i know of, so no, you can't murder under islam.
There are a few instances where you can kill someone, and those include:
- if you are the executioner for someone who has been sentenced to death; in islam there are a few crimes that carry capital punishment, murder being one of them. Most scholars would also include practicing witchcraft, homosexual sex, apostasy (although modern debate includes a very vocal view that what is actually being punished is treason, not public apostasy per se - I'm not sure whether that is more than a minority view at the moment), and adultery (i.e. having sex with someone other than your spouse while you are married). There are varying degrees of burden of proof in procedural law for those, but the material law is quite clear.
- fighting an enemy combatant on the battlefield
- in defense of someone who is being attacked
I'm not aware of any other instances.