The ruling on one who has a small amount of water, uses it for istinja' (cleaning oneself after relieving oneself), and then performs tayammum (dry ablution with clean earth)

Question:
The questioner says: Some people, when water is scarce, use it for istinja' (cleaning oneself after relieving oneself) and then perform tayammum (dry ablution with clean earth). Is that permissible for them?

Answer:
Yes, he should use water for istinja' (cleaning oneself after relieving oneself) and then perform tayammum (dry ablution with clean earth); because istinja' (cleaning oneself after relieving oneself) does not include tayammum (dry ablution with clean earth), so the impurity must be removed. However, if it is easy for him to use dry cleaning (istijmar) when he has access to dry earth or stones, he should use dry cleaning and save the water for wudu' (the ablution for prayer). This is preferable if he knows how to perform dry cleaning. He should use dry cleaning three times or more until the area is purified, using stones, tissues, or dry earth to purify the anus and the penis with dry earth, rough tissues, or stones, three times or more. Then he should save the water for wudu' (the ablution for prayer) to wash his face and hands, wipe his head, and wash his feet. This is preferable if it is feasible.