by the caliphs who succeeded him.

The same ruling applies to a mustaʾman (a non-Muslim granted safe-conduct) who comes into Muslim territory for trade.

Neither the full tithe nor half of it is taken from any amount worth less than ten dinars in either case—that is, when the trader is a ḥarbī or a dhimmī; this is explicitly stated (1). Because this is wealth upon which the Sacred Law imposes a financial right, a minimum threshold (niṣāb) is required for it, just as with zakāt. Ten dinars were specified because the portion due on that amount comes to half a dinar, so it deserved to be treated like the twenty-dinar niṣāb that applies to a Muslim.

Half a tenth is taken from a dhimmī and a full tenth from a ḥarbī only once each year, as explicitly ruled (2). The evidence is the narration: “A Christian came to ʿUmar and said, ‘Your tax-collector has taken the tithe from me twice in a single year.’ ʿUmar asked, ‘Who are you?’ He replied, ‘I am the Christian elder.’ ʿUmar responded, ‘And I am the elder who follows pure monotheism,’ and he wrote to his governor instructing him not to levy the tithe more than once a year,” reported by Aḥmad (3).

Because jizyah and zakāt are collected only once per year, the same applies in this case as well.