(Al-An'aam) 6 : 136
وَجَعَلُوا لِلَّهِ مِمَّا ذَرَأَ مِنَ الْحَرْثِ وَالْأَنْعَامِ نَصِيبًا فَقَالُوا هَٰذَا لِلَّهِ بِزَعْمِهِمْ وَهَٰذَا لِشُرَكَائِنَا ۖ فَمَا كَانَ لِشُرَكَائِهِمْ فَلَا يَصِلُ إِلَى اللَّهِ ۖ وَمَا كَانَ لِلَّهِ فَهُوَ يَصِلُ إِلَىٰ شُرَكَائِهِمْ ۗ سَاءَ مَا يَحْكُمُونَ

And they assign for Lord Allah a share from the crops and cattle that He has produced; then they say: “This is for Allah" according to their claim, and “This is for our deities”. Then anything that is meant for those who are associated with Lord never reaches into Allah, while what is for Allah reaches into those who are associated with Lord, what a wretched judgment they are making.

Meccan pagans used to reserve a small portion of their cultivation to the Lord and another portion of their deities. Whenever crops fall into Lord's portion, they will give it to their deities’ portion justifying that Lord is Self-sufficient while their deities are not. This verse explains the evil superstitious customs of disbelievers during Messenger's time. 

Today, the Arabic Quran reading Fujjar who are reading these verses are having more superstitious beliefs and customs than Meccan pagans who had not received a codified Lord’s Book. Even though Adhikr is codified, the worthless, cursed, wrath-affected Fujjar are not utilizing It and are not giving It to others. They have become the true disbelievers as explained in verses 4: 150-151. See explanation 2: 57, 168-169; 4: 50-51 and 25: 33-34.