Answer
✅ Answer: Please pay attention to the following narrations:
1 عَنِ الرِّضَا فِي كِتَابِهِ إِلَى الْمَأْمُونِ قَالَ: وَ الْخُمُسُ مِنْ جَمِيعِ الْمَالِ مَرَّةً وَاحِدَةً.
📚 Bihar Vol. 10, p. 362
Imam Reza (peace be upon him) said: The one-fifth is from all property only once!
2 عَنْ عِمْرَانَ بْنِ مُوسَى عَنْ مُوسَى بْنِ جَعْفَرٍ قَالَ: قَرَأْتُ عَلَيْهِ آيَةَ الْخُمُسِ فَقَالَ مَا كَانَ لِلَّهِ فَهُوَ لِرَسُولِهِ- وَ مَا كَانَ لِرَسُولِهِ فَهُوَ لَنَا ثُمَّ قَالَ وَ اللَّهِ لَقَدْ يَسَّرَ اللَّهُ عَلَى الْمُؤْمِنِينَ أَرْزَاقَهُمْ بِخَمْسَةِ دَرَاهِمَ جَعَلُوا لِرَبِّهِمْ وَاحِداً وَ أَكَلُوا أَرْبَعَةً حلالا ثُمَّ قَالَ هَذَا مِنْ حَدِيثِنَا صَعْبٌ مُسْتَصْعَبٌ لَا يَعْمَلُ بِهِ وَ لَا يَصْبِرُ عَلَيْهِ إِلَّا مُمْتَحَنٌ قَلْبُهُ لِلْإِيمَانِ.
📚 Basa'ir al-Darajat p. 49, narration 5
Imran ibn Musa said: I recited the verse of the one-fifth to Imam Kazim (peace be upon him), and the Imam said: What is for Allah is for His Messenger, and what is for His Messenger is for us!
Then he said: By Allah, the Lord has made the provision of the believers easy for them with five dirhams, so that they set aside one dirham for their Lord and eat the other four dirhams as lawful!
Then he said: This is from our difficult and very difficult hadiths, which no one acts upon and endures except for one whose heart has been tested for faith!
✅ From the above narrations and others, it is clear that khums is due on each property only once, and a property on which khums has been paid, no other khums is obligatory on that property, even if more years pass.
اللَّهُمَّ فَصَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ