What is the ruling on combining and shortening prayers for a traveler while doubting the purity of their garment?

Whoever resolves to stay in a country for four days or more—excluding the days of arrival and departure—is not permitted to shorten prayers, nor is he allowed to combine them except for an excuse. You are obliged to repeat the ‘Isha prayer in full if you performed it before its due time, because you are neither a traveler nor considered as one.