I watched the prayer of Muhammad (may Allah's peace and blessings be upon him) and found his standing, his bowing, standing after bowing, prostration, sitting between the two prostrations, prostration, and sitting between Taslīm (end of the prayer) and going away nearly equal to one another

Al-Barā ibn ‘Āzib (may Allah be pleased with him) describes the Prophet's prayer as he watched him closely to learn how he prayed and follow his example. He mentioned that all the Prophet's postures were in proportion. So, his standing for recitation and sitting for the Tashahhud were proportional to bowing, standing up after bowing, and prostration. He would not prolong his standing and shorten his bowing, nor would he prolong his prostration and shorten his standing.

Rather, he would keep each posture commensurate with others. This does not mean that his standing and sitting for Tashahhud were exactly equal in length to his bowing and prostration. It means that he would not shorten one and prolong the other.