ثُمَّ ارْكَعْ حَتَّى تَطْمَئِنَّ رَاكِعًا، ثُمَّ ارْفَعْ حَتَّى تَعْتَدِلَ قَائِمًا
Meaning: Then bow until you have settled in bowing; then rise until you stand upright.
The same narration directs composure in prostration and in the sitting between two prostrations. The repeated “until” emphasizes completing each posture before moving to the next.