وَإِنِ افْتَتَحَهَا قَائِمًا ثُمَّ قَعَدَ جَازَ عِنْدَ أَبِي حَنِيفَةَ.
Translation: If one begins nafl while standing and then sits, it is valid according to Abu Hanifa.
For Abu Hanifa, since voluntary prayer may begin seated, sitting later during the same prayer is also valid. Initial standing does not create a separate standing duty for all later rakahs.
Validity and the greater merit of standing remain separate issues.
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Voluntary Prayers: Regular Sunnahs, Nawafil and Juristic Differences
وَإِنِ افْتَتَحَهَا قَائِمًا ثُمَّ قَعَدَ جَازَ عِنْدَ أَبِي حَنِيفَةَ.
Translation: If one begins nafl while standing and then sits, it is valid according to Abu Hanifa.
For Abu Hanifa, since voluntary prayer may begin seated, sitting later during the same prayer is also valid. Initial standing does not create a separate standing duty for all later rakahs.
Validity and the greater merit of standing remain separate issues.