Is it permissible to perform Tayammum using salty ground (Sabkha) or sand (Raml)?
Chapter on Tayammum
Al-Mughni
Book of Purification
Primary text
There is a narration from Ahmad, may Allah have mercy on him, stating that it is permissible to perform Tayammum with salty ground (Sabkha) and sand (Raml). Abu al-Harith narrated that Ahmad preferred arable land, but performing Tayammum with salty ground suffices. Al-Qadi specified that the location is permissible if it possesses dust, and impermissible if it lacks dust; the same criterion may apply to sand. Another narration from Ahmad states that this is only permissible under necessity. The narration from Sindi indicates that arable land is superior to salty ground, lime plaster (Nawrah), and pebbles (Hasa), but if one is forced to use the latter, it suffices.
Supporting text
Al-Khall clarified that Ahmad permitted this only when necessitated, provided the salty ground has dust resembling soil. If it is entirely saline, like salt, Tayammum should not be performed with it at all. Ibn Abi Musa stated that in the absence of soil, Tayammum may be performed with any pure substance that rises to the earth's surface, such as sand, salty ground, lime plaster, or kohl, and prayer performed with it requires further clarification regarding necessity of repetition (repetition is subject to two narrations).