I say, and with God's success: If Zayd has ten dinars owed to 'Amr, and 'Amr has one hundred dirhams owed to Zayd, it is permissible for them to offset their debts to the extent they agree upon, and the possession will be deemed as such. Any excess debt of one over the other after the offset will remain established in his obligation, and this is similar to what is found in the jurisprudence of sales (2: 670), and God knows best.