First of all I have to correct myself on a couple of points...I was wrong in making what the Holy Prophet disliked and correlating that with what is mukruh. My apologies.
Going back to your post...Well he liked the taste of squash...was that an order from Allah?
Hadhrat Gibrail taught him how to pray and then he taught us how to pray.
Of course and I have to correct myself on the other point here; which is that the Holy Prophet has made things haram which were not mentioned in the Qur'an, however...he did not forbid anything by his own volition but by orders from Allah.
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That's a very vague question.
In the Qur'an Allah states:
22:40 Permission to fight is given to those against whom war is made, because they have been wronged - and Allah indeed has power to help them -
'And fight in the cause of Allah against those who fight against you, but do not transgress. Surely, Allah loves not the transgressors.' (Al-Baqarah, 191)
The greatest Jihad (struggle) is the Jihad of the self, i.e. the inner struggle with oneself.
In a state of war where you're defending yourself from the aggressor and you find yourself with limited resources and are forced to strap yourself with explosives and you're not are not aiming to kill innocent civilians then I don't see why it would be unlawful. For example, in the Indo-Pak war of 1965 Pakistani soldiers strapped themselves with explosives and hid in tiny foxholes to take out Indian tanks as they were closing in on Lahore. That was out of necessity.
If I was asked to defend my country, the US, for whom I've pledged to defend, and it were to find itself in such a situation then I'd have to do it.
Hope that answers your question.