The Command to eat Pure Things and the Explanation of the Prohibited Things

Allah commands His believing servants to eat from the pure things that He has created for them and to thank Him for it, if they are truly His servants. Eating from pure sources is a cause for the acceptance of supplications and acts of worship, just as eating from impure sources prevents the acceptance of supplications and acts of worship, as mentioned in a Hadith recorded by Imam Ahmad, that Abu Hurayrah said that Allah's Messenger ﷺ said:

«أَيُّهَا النَّاسُ إِنَّ اللهَ طَيِّبٌ، لَا يَقْبَلُ إِلَّا طَيِّـبًا، وَإنَّ اللهَ أَمَرَ الْمُؤْمِنِينَ بِمَا أَمَرَ بِهِ الْمُرْسَلِينَ، فَقَالَ:

The wordإِنَّمَا حَرَّ‌مَ (innama harrama) is a restrictive particle, therefore, the sense of the verse is that Allah Almighty has forbidden only those things which have been mentioned later, other than which, nothing else is forbidden. So, in this verse, it is the word, innama إِنَّمَا which points out to the given sense, while in another verse (6:145): قُل لَّا أَجِدُ فِي مَا أُوحِيَ إِلَيَّ مُحَرَّ‌مًا عَلَىٰ طَاعِمٍ the same thing has been stated more clearly. Here, the Holy Prophet ﷺ has been asked to proclaim that, in what has been revealed to him, there is nothing haram حرام except the few things mentioned later on.

At this stage, we have a problem on our hands. The fact is that the unlawfulness of many things stands proved on the authority of other verses from the Qur'an, and also from ahadith. If so, what would be the meaning of this 'restriction' and how are we to explain the negation of 'there is nothing haram حرام except the few things mentioned later on'?