"When Allah's Messenger performed the Takbir for Salat he would spread his fingers."
Jami` at-Tirmidhi Book 2, Hadith 91
← Previous Hadith Allah's Messenger said: "the key to Salat is the purification, its Tahrim is the Takbir, and its Tahlilis the Taslim, and there is no Salat for one who did not recite Al-Hamd and a Surah in the obligatory (prayer) or other prayers."

Jami` at-Tirmidhi Book 2, Hadith 90 Next Hadith → "When Allah's Messenger would enter the Salat he would raise his hands while they were extended."

Jami` at-Tirmidhi Book 2, Hadith 92