Hazrat Abu Maisarah says that it is permissible to rub the stone that has been used for istinja, or to use its other side for istinja.

Hasan says that if a stone is large and has different edges, then it is permissible to perform istinja with its other edge.

Hazrat Mujahid says that it is disliked to use a stone for istinja (purification) which has already been used for istinja.

Hazrat Sha'bi says that it is forbidden to perform istinja with dung and bone.

Hazrat Ammar narrates that once I had gone out to graze the camels when I became junub, and there was no water available. So I began to roll in the dust like an animal. Then I presented myself before the Messenger of Allah (peace and blessings be upon him) and related the whole matter. The Prophet (peace and blessings be upon him) said that tayammum would have been sufficient for you.

Hazrat Imran bin Husain narrates that the Messenger of Allah, peace and blessings be upon him, led the people in prayer during a journey. He saw that a man was standing apart from the people in a corner. He asked, "Why did you not pray with the people?" He replied, "O Messenger of Allah! I became junub and did not find water." The Prophet, peace and blessings be upon him, said, "You could have performed tayammum with earth; that would have been sufficient for you."

It is narrated from Hazrat Abu Dharr that the Messenger of Allah, peace and blessings be upon him, said: "Pure earth is a purifier for you as long as you do not find water, even if ten years pass. When you find water, then use it on your skin."

It is narrated from Hazrat Hudhaifah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: When we do not find water, the earth's soil has been made a means of purification for us.

Hazrat Ali (may Allah be pleased with him) says in the explanation of this verse: { وَلاَ جُنُبًا إِلاَّ عَابِرِی سَبِیلٍ } That is, a traveler who does not find water should perform tayammum and offer prayer.

Hazrat Hasan bin Muslim, in the explanation of this verse, says: { وَلاَ جُنُبًا إِلاَّ عَابِرِی سَبِیلٍ } that if you are a traveler, then perform tayammum.