Who establish and consolidate the Divine System and set up the Just Economic Order of Zakat. They have conviction in the life to come (that the human "Self" lives on after death, and that all actions meet a just requital)
The believers are those who worship God on regular basis and devote a portion of their incomes/ resources to charity and believe that there is a life after death [and that this earthly life is a short prelude to an everlasting life]
Faridul Haque
Those who keep the prayer established and pay the charity and are certain of the Hereafter
Hasan Al-Fatih Qaribullah
who establish their prayers, and pay the obligatory charity, and are certain of the Everlasting Life
Those who perform AsSalat (IqamatasSalat) and give Zakat and they believe with certainty in the Hereafter (resurrection, recompense of their good and bad deeds, Paradise and Hell, etc.)
Who perform salat (experience ascension [miraj] by turning to Allah) and give from their possessions in order to become purified and refined; it is they who have attained certainty of their immortal life to come.
Sayyed Abbas Sadr-Ameli
Those who establish prayer and give Zakat (the poor-rate), and of the Hereafter, they are sure
Al-muntakhab fi tafsir al-Qur'an al-Karim
Who engage in the act of worship and give alms -for alms are but the vehicles of prayer- and look at the Hereafter as the most undoubted event