Your treatise is brilliant as usual.
"Mushaf Al-Madinah An-Nabawiah" regularly printed in Saudi Arabia for free distribution has an interesting footnote under 4:12 (Surah 4 verse 12), page 211 in my copy.
"... kalalat ... was one of the three terms about which Hazrat Umar wished that the Messenger had defined them in his lifetime, the other two being the share of the grandfather, and riba (usury)."
A few years ago the famous Pakistani scholar, Dr. Israr Ahmad, chaired a committee for two years trying to elaborate and devise a system of "Interest Free Economy" in Pakistan. Their accomplishment: The committee adjourned after two years of deliberations and failed to establish even a unanimous definition of riba.
Did Allama Iqbal make it clear? Decide for yourself:
ZAAHIR MEIN TIJARAT HAI HAQEEQAT MEIN JUA HAI
SOOD AIK KA LAKHON KAY LI'AY MARG-E-MAFAJAT
(Apparently trade, Sood (riba) is, in fact, gambling. The Sood of one is the sudden death to hundreds of thousands.)
Allama G.A. Parwez believed riba to be a deplorable integral part of, and at times synonymous with, Capitalism.
Me: The above quotation attributed to Hazrat Umar appears to be a fabrication since it tends to insult Allah, the exalted Messenger and one of his greatest companions. Waiting for comments from our gifted friends, I would hold more of my thoughts at this time.