Tafsir of At-Tahreem 66:9

"O Prophet, strive against the disbelievers"—with the sword—"and the hypocrites"—with argument and evidence—"and be harsh with them"—employ severity against both groups in the manner in which you strive against them, once gentleness has reached its limit.

It is narrated from al-Hasan that the majority of those upon whom the prescribed legal punishments (hudud) were carried out during that era were the hypocrites; thus, he (peace and blessings be upon him) was commanded to be harsh with them in the execution of these punishments.

Al-Tabarsi narrated from al-Baqir that he recited it as "Strive against the disbelievers by means of the hypocrites." I suspect this is among the falsehoods of the Imamiyyah—may Allah, Exalted is He, treat them according to His justice.

"And their refuge is Hell"—that is, they shall experience therein a severe punishment—"and wretched is the destination"—meaning Hell, or their refuge. The conjunction is said to be the linking of one account to another.