ijtihād is only undertaken while he is alive when he is physically absent and far from the person requesting the ruling.

8. The scholars differed over whether one may perform tayammum with everything that rises from the surface of the earth:
   • Imām al-Shāfiʿī and Imām Aḥmad held that tayammum is valid only with soil that leaves dust on the hand. They argued from the Divine statement, “then wipe your faces and your hands with some of it” (al-Māʾidah 5:6); if the substance has no dust, nothing adheres to the hand, so tayammum with it is invalid. They also cited Muslim’s narration from Ḥudhayfah in which the Prophet ﷺ said, “The earth has been made a mosque for us, and its soil a means of purification for us.”
   • Imām Abū Ḥanīfah and Imām Mālik, on the other hand, deemed tayammum permissible with anything that lies on the earth—whether dusty or not—such as sand, pebbles, saline soil, moist ground or dry, burnt or unburnt, stone, grass, trees, and whatever may rest upon them, including carpets, animals, and the like. They exclude nothing that is on the earth’s surface. This view was also adopted by al-Awzāʿī and Sufyān al-Thawrī.

Al-Nawawī said: this is one opinion within our own school as well. It is the second report from Imām Aḥmad, preferred by Shaykh al-Islām (Ibn Taymiyyah) and Ibn al-Qayyim, deemed weightier by Ibn Mufliḥ in al-Furūʿ, and affirmed in al-Inṣāf. Their evidence is the verse, “then perform tayammum with clean earth” (al-Māʾidah 5:6), and the Prophet’s ﷺ statement, “The earth has been made for me a place of worship and a means of purification.”

Thus, the general purport of the texts indicates that tayammum is permissible with anything that rises from the surface of the earth.