Reference: Al-Muntaqaa – Question 22, v. 5 p. 19
Question: If a man performed the Fajr prayer in a state of Tayammum because there was no water, would he then have to repeat his prayer if he [later] found water after the sun had risen?
Response: If he performed Tayammum during the time [of prayer] and prayed because he did not have any water, then his prayer is valid. And thereafter, if he found water, even before the passing of the time [of that prayer] then he is not [required] to repeat his prayer, because the prayer he just performed was done so in a state of legislated purity which Allah (Ta’aala) has commanded with, so he is not [required] to repeat it.
Allah (Ta’aala) says:
{…and you find no water, perform tayammum with clean earth and rub therewith your faces and hands…}, [Soorah an-Nisaa., Aayah 43]
However, if water was found [or made available] before the completion of the prayer, then the prayer [being performed] is invalidated [due to the availability of the water] and it is obligatory upon him to purify himself with the water and perform the prayer in [a state of] wudhoo.
صلاة الفجر متيمماً لعدم وجود الماء
المرجع: المنتقى من فتاوى فضيلة الشيخ صالح بن فوزان بن عبد الله الفوزان – السؤال 22، الصفحة 19، المجلد 5
السؤال: إذا صلى الرجل صلاة الفجر متيمماً لعدم وجود الماء و حصل على الماء بعد طلوع الشمس فهل عليه إعادة الصلاة؟
الجواب: إذا تيمم في الوقت و صلى لأنه لم يكن عنده ماء فصلاته صحيحة، و إذا وجد الماء بعد ذلك و لو قبل خروج الوقت فإنه لا يعيد الصلاة، لأن صلاته التي صلاها تمت بطهارة شرعية قد أمر الله تعالى بها فلا يعيدها قال الله تعالى:
{فلم تجدوا ماء فتيمموا صعيداً طيباً فامسحوا بوجوهكم و أيديكم} [سورة النساء، آية 43]
أما لو حضر الماء قبل انقضاء الصلاة فإنها تبطل و يلزمه التطهر بالماء و الصلاة بوضوء.
