Hadith: I have been commanded to fight people until they testify that there is no god but Allah and that Muhammad is the Messenger of Allah, establish prayer, and pay Zakah

عَنِ ابْنِ عُمَرَ رضي الله عنهما أَنَّ رَسُولَ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ:
«أُمِرْتُ أَنْ أُقَاتِلَ النَّاسَ حَتَّى يَشْهَدُوا أَنْ لاَ إِلَهَ إِلَّا اللَّهُ، وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ، وَيُقِيمُوا الصَّلاَةَ، وَيُؤْتُوا الزَّكَاةَ، فَإِذَا فَعَلُوا ذَلِكَ عَصَمُوا مِنِّي دِمَاءَهُمْ وَأَمْوَالَهُمْ إِلَّا بِحَقِّ الإِسْلاَمِ، وَحِسَابُهُمْ عَلَى اللَّهِ».
[صحيح] - [متفق عليه] - [صحيح البخاري: 25]

Ibn ‘Umar (may Allah be pleased with him and his father) reported that the Messenger of Allah (may Allah's peace and blessings be upon him) said:
"I have been commanded to fight people until they testify that there is no god but Allah and that Muhammad is the Messenger of Allah, establish prayer, and pay Zakah; if they do so, they protect their blood and properties from me, except through the right of Islam; and their reckoning is with Allah."
Sahih/Authentic. - [Al-Bukhari and Muslim with all its versions]

Explanation

The Prophet (may Allah's peace and blessings be upon him) informs that Allah commanded him to fight the polytheists until they testify that no deity is truly worthy of worship except Allah alone without any partner and that Muhammad (may Allah's peace and blessings be upon him) is His Messenger and act upon this testimony by observing the five prayers every day and night and paying the obligatory Zakah to those who are entitled to receive it. If they do these things, Islam protects their lives and properties, and it, thus, becomes unlawful to kill them unless they commit a crime or felony that makes them worthy of being killed in compliance with the rulings of Islam. Then, on the Day of Judgment, Allah Almighty will be in charge of their reckoning as He knows their innermost thoughts.