What is the ruling on washing a dirty part of the body during ablution and before its turn in the sequence, then completing the ablution from where it stopped?

The Shāfiʿīs and Ḥanbalīs are of the view that sequence (tartīb) in ablution (wuḍūʾ) is obligatory, whereas the Ḥanafīs and Mālikīs consider it to be a Sunnah. If someone performing ablution washes their face, then washes some dirt from their forearm, and then returns to complete washing their face, followed by the rest of the limbs in sequence, their ablution is valid. As for someone who completes their ablution and then washes their hand, their ablution is also valid, because the ذكر (dhikr) mentioned after ablution is a Sunnah and does not fall under the issue of sequence.