Raising the hands (like at the beginning of the prayer) when going into bowing (rukū‘):
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ ، ‏‏‏‏‏‏عَنْ مَالِكٍ ، ‏‏‏‏‏‏عَنِ ابْنِ شِهَابٍ ، ‏‏‏‏‏‏عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ ، ‏‏‏‏‏‏عَنْ أَبِيهِ ، ‏‏‏‏‏‏أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ كَانَ يَرْفَعُ يَدَيْهِ حَذْوَ مَنْكِبَيْهِ، ‏‏‏‏‏‏إِذَا افْتَتَحَ الصَّلَاةَ وَإِذَا كَبَّرَ لِلرُّكُوعِ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ رَفَعَهُمَا، ‏‏‏‏‏‏كَذَلِكَ أَيْضًا، ‏‏‏‏‏‏وَقَالَ:‏‏‏‏ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ رَبَّنَا وَلَكَ الْحَمْدُ، ‏‏‏‏‏‏وَكَانَ لَا يَفْعَلُ ذَلِكَ فِي السُّجُودِ.
Narrated by Abdullah ibn Maslama, from Mālik, from Ibn Shihāb, from Sālim ibn Abdullah, from his father, that the Messenger of Allah (may Allah bless him and give him peace) used to raise his hands in line with his shoulders when he opened the prayer, and when he said takbīr for bowing, and when he raised his head from bowing, he would do the same. And he said: “Allah hears the one who praises Him. Our Lord, to You belongs all praise.” He did not do that in prostration.
(Sahih al-Bukhari, 735)
The Prophet (may Allah bless him and give him peace) used to recite different supplications in this position—sometimes this one and sometimes that one. Among them was:
“Subhāna rabbiyal-‘azīm”
Translation:
Glory be to my Lord, the Most Great.
He would say it three times, and sometimes more than three.