Am I required to seek permission when transferring Islamic topics from other forums to my free forum, and is my action considered sinful?

It is obligatory to attribute quotations to their sources, as this embodies academic integrity and the truthfulness of knowledge. Sufyan al-Thawri said: "Attributing a benefit to its originator is part of the truthfulness of knowledge and gratitude for it, while remaining silent about it is a lie in knowledge and a rejection of it." Al-Nawawi said: "Among sincere advice is to attribute an uncommon benefit to its author. Whoever does so will have blessings in his knowledge and his state. But whoever creates the illusion that what he takes from the words of others is his own, is deserving that his knowledge will not benefit him, nor will his state be blessed."