Sa'id bin Abi Ayoub سعيد بن أبي أيوب الخزاعي · The Book on Faith

"A delegation of Abdul-Qais came to the Messenger of Allah (ﷺ) and said: 'We are a tribe from Rabi'ah, and we cannot come to you except during the sacred months. So order us with something that we can take from you, and then we call those who are behind us to it.' So he said: 'I order you with four things: To testify to La Ilaha Illallah, and that I am the Messenger of Allah; to establish the Salat, to…

that the Messenger of Allah (ﷺ) said: "Do you know what Allah's right upon His slaves is?" I said: "Allah and His Messenger know best." He said: "His right upon them is that they worship Him alone and do not associate any partners with Him." He said: "And do you know what their right over Allah is if they do that?" I said: "Allah and His Messenger know best." He said: "That He will not punish them."