Legislation on Deliberately Adding to Recommended Acts in Prayer

Question

Is deliberately legislating something recommended in prayer invalidating or forbidden? Thank you.

Answer 1

Peace be upon you and God's mercy and blessings.

Grand Ayatollah Sayyid Khamenei (may God protect him):

If a person adds or omits a pillar of prayer intentionally or forgetfully, or intentionally adds or omits a non-pillar obligatory part, their prayer is invalid.

Source: Special Inquiry.

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Grand Ayatollah Sayyid Sistani (may God protect him):

If someone intentionally neglects any part of the prayer or its conditions, their prayer is invalid, even if it is just a letter or a movement in recitation or remembrance. Similarly, if someone intentionally adds a part, whether by saying or acting, there is no difference between a pillar and other parts, nor between intending it at the beginning or during the prayer.

Source: Minhaj al-Salihin, Vol. 1, Book of Prayer » Chapter Ten: Errors in Prayer.

May you be successful in all good.