This question which asks about the origins of the Al-Quds International Day and how it is related to Islam was closed for being off-topic on the pretext of being related to muslim culture or behavior and unrelated to the study of Islam.
However Al-Qud Day is an annual international event held by muslims, first announced by Ayatollah Khomeini, the founder of Islamic Republic of Iran, a high ranking scholar of religion, based on the Islamic principle of supporting the oppressed against oppressors.
So it can arguably be regarded as an Islamic event rooted in the sociopolitical teachings of Islam, and therefore very well part of Islam. That negates the mentioned off-topic close reason.
Discussing it in chat, some users questioned the question in other ways, mainly that this is a political question that may cause unease for Jewish viewers of the site. But this is not a good reason to close down an Islamic question simply because some other group doesn’t like it! Imagine an atheist posting a question in philosophy.SE asking for arguments against God’s existence. Since the very nature of the question makes it a completely valid on-topic philosophical question, it is not reasonable to say it should be closed down for it causes unease for Theist viewers of the site!
That is, personal preferences or sentiments should not get in the way of a question with a sound intellectual basis. Plus a community with distinct beliefs and concerns should not be expected to entirely appeal to every other community of the people in other circumstances. Therefore, it is the interests and concerns of the host community that should count and be respected, primarily.
Plus as for the particular question, facts of Israeli occupation of Palestine and oppression of Palestinians are so widely known and documented that can be hardly disputed objectively. In short, Israel is a state bestowed by British Colonialism on Jewish Diaspora recognized by UN majority vote but against the consent of the indigenous Arab nations and governments of the region. Israel is therefore an occupational government forced through unjust legalities and brute military force upon an unwilling indigenous people. This is indisputable fact of history.
So in the light of the sociopolitical teachings of Islam, Islamic scholars are essentially qualified by Islam to issue fatwas calling for actions in respect to Israeli occupation. Therefore before shying away from such Islamic political issues, every non-muslim must realize that Islam is a religion that explicitly addresses the sociopolitical aspects of muslims' life, and consequently scholars of Islam issue rulings on real problems that muslim face in their daily lives including the sociopolitical spheres of life. And these rulings can be addressed as part of the study of Islam. And in fact there's been no shortage of Islamic rulings and theories on questions of politics in history of Islam.