بسم الله الرحمن الرحيم
لِمَن شَاءَ مِنكُمْ أَن يَسْتَقِيمَ "To whomsoever among you who wills to walk straight." [Al-Quraan 81:28]
Shaykh Muhammad Ibn Saalih Al-'Uthaymeen: "Here, the Arabic noun for the verb used is اِسْتِقَامَة (istiqaamah) which means 'moderation.' And there is nothing more moderate or just than the justice found within Allaah's Legislated religion. Previous legislations were suitable for earlier nations, appropriate for their time, place, and circumstances. Likewise, after the mission of the Messenger Muhammad (صل الله عليه وسلم), the Legislation he brought is suitable and applicable to those to whom he was sent – everyone from the beginning of his mission until the end of this world.
There is a well-known saying in our religion: The religion of Islaam is suitable and ensures the well-being of every time, place, and circumstance. When people stick to it, Allaah corrects the affairs of creation.
Consider that a person is instructed to pray standing. If he is unable to stand, then sitting, and if unable to sit, he may pray lying down. In this way, the religion is suitable and easily applied — and progressive — according to the circumstances of each individual. This religion is appropriate for every time, place, and condition.
Similarly, someone who washes for prayer may use water if he is able or has it. Otherwise, he may use clean sand or even pray without washing at all. This is because Allaah's religious Legislation, all of it, is based on moderation and justice. There is no unfairness, discrimination, oppression, strictness or hardship in it. For this reason, Allaah refers to it as 'the straight path'. - 2 minutes ago