“Establish the prayer and pay the zakah.” Establishing the prayer means performing it correctly, just as it came from the Prophet ﷺ; paying the zakah means handing it over to those who are entitled to it. The meaning of zakah and its benefits have already been discussed, as far as Allah has enabled.
Next he cites the second verse: “They were only commanded to worship Allah, devoting the religion exclusively to Him as upright monotheists, to establish the prayer and to give the zakah; that is the upright religion.”
“They were only commanded” refers to all people. “To worship Allah” means to humble themselves to Him through every act of devotion He has legislated—be it creed, word, or deed. “Devoting the religion exclusively to Him” means keeping one’s deeds purely for Allah; sincerity in action is that a person seeks nothing by it except Allah—no worldly gain, no prestige, no leadership, nothing at all—only Allah’s reward. His phrase “as upright monotheists” means turning away from polytheism: pure devotion without associating partners. Then comes “to establish the prayer and to give the zakah,” and our point of evidence lies in “to give the zakah.”
His words “that is the upright religion”: “that” refers to worshipping Allah with sincere devotion, establishing the prayer, and paying the zakah. “The upright religion” is the sound, straight religion; these are the deeds that earn Allah’s approval.
The Exalted also says, “Take from their wealth a charity,” an address to the Prophet ﷺ. “Take from their wealth a charity” means the zakah, “by which you purify them and cause them to grow, and pray for them.” It purifies them from sins and from disgraceful traits. As for its purifying them from sins, He said—