Is it obligatory to repeat the Dhuhr and Asr prayers after having combined them by way of taqdim (advancement) during the time of Asr by mistake?

If someone intended to combine prayers (jama' taqdim), so he prayed Dhuhr and Asr, then it became clear to him that he prayed them during the time of Asr, his prayer is valid and he does not need to repeat it. This is because the Asr prayer occurred within its prescribed time, and delaying Dhuhr beyond its time without intending to combine prayers by way of jama' ta'khir is excusable due to his assumption that the time for Dhuhr was still remaining. The jurists have explicitly stated that if someone prays Dhuhr intending it as an اداء (performance within its time), but it turns out to be a قضاء (make-up prayer), his prayer is valid and counts as a قضاء.

The general rule for jama' ta'khir is that its intention should be made during the time of Dhuhr, before its time becomes constrained, and that it is not permissible to delay a prayer beyond its time except for someone who is permitted to combine prayers and intends to do so.

Some jurists — and this is the well-known view in the Hanbali school — stipulate the intention for combining prayers, whether taqdim or ta'khir. However, Sheikh al-Islam Ibn Taymiyyah holds that the intention for combining prayers is not a condition for jama' taqdim, and this is the correct view. Based on this, the Asr prayer performed during the time of Dhuhr is valid and sufficient, especially since a traveler has the choice between jama' taqdim and jama' ta'khir.