Two steps: one is most beloved to Allah and the other is the most hateful of steps to Allah

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) relates: We did not know what to say when we sat in the prayer, and the Messenger of Allah (peace and blessings be upon him) had been taught comprehensive and complete words. He (peace and blessings be upon him) taught us the tashahhud, and he also taught us these words: 'Allahumma allif bayna qulubina, wa aslih dhata baynina, wahdina subulas-salam, wa najjina minaz-zulumati ilan-nur, wa jannibnal-fawahisha ma zahara minha wa ma batan, wa barik lana fi asma'ina wa absarina wa qulubina wa azwajina wa dhurriyyatina, wa tub 'alayna innaka antat-Tawwabur-Rahim, waj'alna shakirina li-ni'matika, muthnina biha 'alayka, qabiliha, wa atmimha 'alayna' (O Allah, create affection between our hearts, set right our mutual affairs, guide us to the paths of peace, bring us out of the darknesses into the light, keep us away from indecencies, whether open or hidden, bless us in our hearing, our sight, our hearts, our wives and our children, and accept our repentance; indeed You are the Accepter of repentance, the Most Merciful. Make us grateful for Your blessings, praising You for them and accepting them, and complete them upon us).
This hadith is sahih on the condition of Muslim, but the two Shaykhs did not record it.

A similar narration is reported from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) through another chain, in which the same words taught by the Messenger of Allah (peace and blessings be upon him) are mentioned.

Abd al-Rahman bin Abd al-Qari relates that he heard Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) teaching the people the tashahhud from the pulpit, saying: Say: 'At-tahiyyatu lillah, az-zakiyatu lillah, at-tayyibatu lillah, as-salamu 'alayka ayyuhan-Nabiyyu wa rahmatullahi wa barakatuh, as-salamu 'alayna wa 'ala 'ibadillahis-salihin, ashhadu an la ilaha illallah, wa ashhadu anna Muhammadan 'abduhu wa rasuluh' (All verbal worship is for Allah, all pure worship is for Allah, all financial worship is for Allah. Peace be upon you, O Prophet, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous servants of Allah. I bear witness that there is no god but Allah, and I bear witness that Muhammad (peace and blessings be upon him) is His servant and Messenger).