Ruling 1595 - 6. Remaining in a state of janābah, ḥayḍ, or nifās until the time of ṣubḥ prayers

If someone knows that he does not have time to perform ghusl and intentionally becomes junub and then performs tayammum, or if despite having time he intentionally delays performing ghusl until the time becomes short and then performs tayammum, in these cases, although he commits a sin, his fast is valid.