The first four priorities are:
1. Most knowledgeable in the rulings of prayer — especially what makes Salah valid or invalid, provided he can recite what is required.
2. Best Quran reciter among those otherwise suitable.
3. Most Wara' — most careful about avoiding prohibited and doubtful matters.
4. Oldest.
This order corrects the earlier abbreviated list that skipped parts of the author's full sequence.